So ended up pulling the trigger on a mini lathe. Going to start getting the tooling ready to go. I still planning on getting a couple of commercial cans but my Original Form 1 still impresses me when compared to commercial units. I no longer have access to the lathe I lathe I had available when I built it about 7 years ago or so.

Now its time to file a form 1 and take some time. Since that whole fiasco with DM and the AFT. Sounds like the process has changed a bit. So going to have to read through and get a celebratory form in and find some metal to practice again.

Congratulations.

Being able to make anything you can dream up, is beneficial in a lot of ways.  This being a big one.

Mini lathes are very picky in terms of the set up.  You’ll need to tweak everything for minimum clearance without binding to get decent precision, and readjust it more often than a larger lathe.

But you can do very good work on them.

I'm in the same boat. Found a good deal on a vevor 8x32" lathe with a bunch of tooling. The top slide and quick change tool post leave a lot to be desired, but I haven't even gone through it yet and I've been impressed with the surface finish it's capable of in steel and aluminum with the right tooling. I plan on replacing the spindle bearings and removing the top slide for a solid block spacer and just giving the whole machine a once over before doing any remotely precise work on it. The only downside is it's a metric lathe, so it's very limited in standard thread pitches, but there are a couple that overlap standard thread pitches that I can use. Worst case scenario, I end up making the end caps proprietary and either make my own muzzle devices or just direct thread to the barrels since the calibers I want to host the suppressors are all 28tpi, which I can do. I might be able to get a set of standard gears for it, but I'm not sure if those are available, I need to look into it. I'm going to do a rimfire can and a couple .45 cal cans later this year hopefully. Still have to submit the form 1's.

There may be change gears that get you very close. A 127 tooth gear can get exact conversion as it’s five times 25.4.  This size gear won’t fit on smaller lathes, but an 8 x 32 should be big enough if that gear exists / available. My Atlas 618 uses the combo of 52 and 44 to get very very close to true metric from an inch lead screw, so there may be a similar combination for metric lead screws if the 127 gear is unobtanium.

It will be nice to be able to do 24 tpi inside 1.335 ID tubes to take Bravo threaded mounts, or cut your own Plan B / Cherry Bomb threads at 0.900” x 24 tpi. Another useful thread is Griffins 1” x 20 tpi. Griffin taper is 15 degrees included angle and IIRC Plan B is 25 degrees.  You need to fit tapers for contact with Prussian blue or similar unless your compound protractor is magical.

With taps centered by the tail stock you can do female 1/2-28 or 9/16-24 or 5/8-24. Concentricity for a mounted device is driven by shoulders cut perpendicular to the bore.  But a bad quality tap can add error if it doesn’t follow a bored hole decently.

I finally started breaking my mini lathe down today and I'm happy to find that just about every screw and bolt is barely finger tight and the cross slide rocks like crazy. Happy because this means I can improve what was already, in my opinion, decent results. I don't have a great way to measure concentricity or perpendicularity at this point, but if I set up everything to the best of my ability I think I can get acceptable results. I spent about 9 years building and setting up CNC production machinery in a machine shop so I think with my experience I should be able to get this thing running tip-top without much fuss. I wish I had access to the equipment I used to use. I had a whole metrology lab at my disposal, with Cmm's, romer arms, laser trackers and calibrated measuring equipment but not anymore.

But I have a few tricks up my sleeve

I bet you can get the SAE gear sets. VEVOR just sells stuff, doesn't make stuff and most small lathes are built up off the same basic Chinese lathes.  
For steel, look at 12L14. The "L" is for lead and makes it really easy to machine. And if you want drill rod to check alignment, look at Zoro Select on ebay. Dirt cheap and mine were read straight. $5 shipping and came in a way oversized heavy duty tube.