Not too familiar with these but I like that they're a rugged plastic instead of a very dentable metal.  How long do they last?  Also, what type of spouts are they used with?  I've seen some for diesel but not gasoline.  I assume the diesel spout won't work with the gasoline fuel filler on a street car.  Any info would be appreciated as I'm thinking of buying a few of them

The Scepter military fuel cans were outlawed by commies in  Ca law in 2008 I believe. They are almost indistructible  and can still be had on Ebay and occasionaly on CL. They command a good price by todays standards.
They are the xcellent fuel cans.
Also Scepter made fuel nozzels for these , but several youtube videos explain how to make fuel nozzles out of components from common parts from big box stores.
Costco sells 5 gallon scepter cans currently, but they are thinner plastic cans similar  to ones sold at Walmart and other places

Yea, I'm trying to stay away from those thin plastic ones.  I bought one a couple years ago, a small 2.5 gal one, I went to use it this winter and the screw on collar broke.  I actually picked up 1 scepter fuel can at a gun show in chantilly last weekend to try it out but haven't had the chance.  I bought it because it is new and it was $50.   I know that's a great price so I bought it.  I'm thinking about more but wanted to check here first before I drop more $ on them as they tend to sell for twice that amount

Well ypu can still buy scepter water cans that are similar ......

Real MFC's are awesome. I bought 9 a few years ago that were used. They all had a bunch of paint on them. I developed a pretty effective method of cleaning the paint off them and cleaning the inside. If you get one I can go into further detail. The weal spot on all MFCs is the flange, which is the plastic part of the cap that secures the gasket. Most MFC's were used for diesel and do not have viton gaskets. If you expose non viton gaskets to regular gas they will expand slightly and break the flange off. Buy new gaskets no matter what you think the used can has. Its not worth it to guess. User @vatopa (sp?) sells real viton gaskets (they smell like cinnamon new).

Real spouts are hard to come by. There is a big one with 1.25" spout (I think) and a smaller one with a clear tube that will fit into most auto gasoline receptacles. I have the big one because that is what I could wrangle up. Because of this I either use a funnel or a super siphon to transfer fuel.

I love mine. They are a little bit trickier to get up and running because you are buying used than a NATO can but I love them. Well worth the investment. Happy to post pictures if you'd like.

Thanks LT I went ahead and bought another two that are used like new I didnt know about the gaskets.  I assumed if they're on a can for gas, that they would be ok for gas.  But I guess not.  I'll look around for some of the proper gaskets.  If you have any other tips and such, I'd love to hear them.

Thread on sourcing Viton gaskets

I'd just suggest almost automatically replacing the gaskets. The flanges break and are irritating to replace. Exception would be if you sourced them from a friend you trust. Real viton is going to cost you about $8(ish) a gasket.

All of my other tips relate to cleaning. Sounds like you have paint free cans so not much more I can add. I think you made a good choice!

LT, I just received my second can today and it's in very good shape.  My third is coming Saturday.  I checked the gaskets on the two I have and they're a flat  grayish green color, not black.  They also look very good.  The collar straps are sand color just like the cans.  Are they viton gaskets?   I read up on the links you suggested and found them very informative.  Also, if you have any tips for maintenance or cleaning, it's always good to know if you care to share.  Thanks

Source
Basically without a history of your can there isn't a good way to tell if you have viton or not. It comes down to risk assessment. If you roll the dice and its viton you saved $8/can. If you roll the dice and its not viton you will be replacing the flange ~$15 and buying a new gasket ($8) anyway for an additional cost per can of $23. For me I'd just spend the $8 upfront and have peace of mind but its really up to you. You could always IM @vatopa and he will be happy to chat with you about them.

If you have a can with paint on it this is how I ended up getting it off. I used "Goo Gone" and those flat abrasive green kitchen "scrubbies". Cover one side or section of side with goo gone and let it sit for 3-5 minuets. This softens the paint. After it is soft use a paper towel to wipe off the loose paint. Re-coat the can with goo gone and then start scrubbing with the green scrubby. Do not let an area get 'dry'. Keep reapplying the goo gone while you are working. It gets the paint softer and softer. The real secret is not to be stingy with the green scrubby. I used 4x4 sections and flip over once they are full of paint. Just keep tossing them! Don't try and get another 20 scrubs out. Trust me it will be WAY faster if you don't try and stretch the life of the scrubby. I had seriously painted cans. I spent about one hour cleaning each one on average.

Mine were almost spotless in the inside but the couple that had old diesel grunge in them I just rinsed with water. You want to get ALL the water out when you are done. I shook them empty, blew out the vent tube with compressed air and then ventilated the cans with a fan and plastic tube for a full week to ensure the water was all evaporated.

FUEL CAN ORACLE

Lots more information at the above link. It deals with all kinds of cans including MFCs.

where did you get them?

eBay. They're like new, $65 each delivered

Doesn't that just piss you off?  Before the ban they were $25 brand new and shipped right to your door.

I spent $25/each on mine (EE here)  but they needed a lot of TLC.

This just adds to my mantra that the government should be involved in the absolute minimum amount possible. They fuck up almost everything they touch.

Anyone remember when Major's Surplus had surplus MFCs for $10 each?  Bought a bunch of them, wish I had bought more.  

I use the old donkey d**k metal spout for a blitz can... screws right into the scepter opening.

Other than the gasket not staying in when the lid is off, what are the consequences of the flange breaking?  I got several, some years back, with the flanges broken in them and have never had an issue in them sealing and working fine- with the flange completely removed.

It depends on how the flange breaks. I have one that broke in the way you described and other than the vition gasket falling out when I take off the cap its fine. I just have to remember that particular can has a loose gasket. I've also had flanges that crack all the way through the flat disk. When this happens the cap/flange seal is compromised. If you are just using it on a day to day basis and fuel is coming and going from the can frequently there isn't a huge problem however not having a true seal can have negative impacts to the cans ability to store fuel for an extended period without venting its volatile components or allowing water condensation in. YMMV

FVIW vatopa also sells solid viton disks that completely cover the can mouth instead of just the ring. Using these can be an alternative to replacing broken flanges.

Bottom line if it works for you it ain't broken!