Hmmm Im dont know what the story is with the welded trunion holes and I know you said you dont want to get into it, but welding on trunions is IMOO a very bad idea. Id call the trunion junk for anyting but possably a blow back build. with the folder and the other parts not including the reciver id say the kit is worth around $275 including the compliance parts. a unmolested matching kit will bring 300 im adding around $45 for the folder the trunion can be replaced and should be IMOO. the reciver is still worth $55 or so. I based that on what a used reciver is worth compared to getting new one. If you were even going to attempt to use the old trunion you still need/should pull the barrel to do it right for the taping of the threads. For $100 you could have had it rivited to your reciver by a pro (I think)
if it were mine id replace the trunion and build it and enjoy it. there are lots of members here who can help that wont rape you. I saw a member pull a problem barrel pin and barrel for free the other day for a guy who was having trouble. Im not sure what Cost $100 to be welded but it dont sound right. with out all the details I realy cant comment. but a new trunion would have been much less. instead of loosing money on the gun Id spend more and have somthing to show for it in the end. in all likely hood two years from now the money spent getting it right would be a drop in the bucket. there are guys who can legaly do a rivet build for you BTW on a registered reciver.
keep it dont let it beat you . or put it on gun broker with full disclosure and it will sell for exactly what some one is willing to pay for it. or put it here for a fixed price or a cool trade.