Fixing a pre-ban is not that difficult of a job. When the ban ended I took my Bushmaster A2 carbine and replaced the A2 stock with an M4 type stock off the EE, did not care for a bayonet lug so I left the FSB alone. I also took off the barrel and took it to a friend who is a machinist. He had never worked on a gun before but I explained what I needed done and it took about half an hour to turn the last 5/8" barrel down to 0.498" and then thread it with a die while still in the lathe. He did not even charge me labor. My total costs involved were the new stock assembly, the A2 FS, and about $6 for the die for the threads. ADCO and some others have done great work on lots of rifles here, but cost was a big issue to me, as was quality, which is why I went the way I did. The hardest thing to do in the project was taking off the barrel. If you have the tools and ability to do that you can keep your barrel and save lots of $$ for more ammo.
Sarge