I'm not sure exactly which mags go in the conversion kit yet. All I do know is that the mags need to be specific to the kit. Any idea what a preban 30rnd .22 mag goes for? Also where I might be able to find a selection of mags for sale?

What is the conversion? Who makes it?

Like Troy said, it has to be the Ciener conversion kit.  The US Army, Navy, The Colt, and DMPS (which I believe are the same as the Military ones) All use 10 rounders.

Not sure which kit it is yet. I'm going to be picking it up from him this comming week. I figure its probably the ones used by the army for training since he was in the service around the time he got it... No big deal if worst comes to worst I can always buy a couple dozen 10 rounders.

If I remember correctly, the Army mags will fit into a regular USGI mag so you can properly traing mag changes and use your regular gear.

Yes they do i have three of these mags if you know anybody looking

UPDATE!

Picked up the conversion kit today. Along with some extra .223 mags for free from my friend. The .22lr conversion kit is a "Colt." The mag is black and made of hard plastic. It seems to except 11 rounds. Which is kinda odd? Isn't it usually 10 rounds? Anyways works great only a few jams mostly due to the bullet lead mushing up. (** No I'm not using remmington hornet ammo. I'm using winchester X high velocity.**)
If anyones got some mags for sale that fit this kit I am interested in buying. Just let me know and name the price and we will talk.
Peace!