Very good I missed that. Also looking closer the ejector hole seems out of rounded too. So yea these were welded then someone took the time to remove the weld. I hope you didn't pay alot for themThe top bolt appears to have weld filler penetration. The bolt on the bottom lacks the chamfering around the ejector hole.
I think when you consider where the market is today, USGI bolts for $150.00 apiece should have sent you a clear signal. Drill Rifle BoltI got both bolts for $300, but I contacted the seller and he agreed to take them back. There was no evidence of any welding on the rear of the bolts, but there was definitely some unusual (non symmetrical) patterns on the bolt face. When I compared them to some of my other bolts I had laying around, they were clearly not like the rest. I'm pretty certain they were from a drill rifle and that just isn't something I'm interested in.