I'm not gonna blame anyone for anything. Everybody has their right to choose who to deal with. I would do the same way You did: fix all the issues before sale, but if possible buyer insists... let him get what he wants. I would like to have a new gun before my next game day- 19-20 th of March, check it, etc. So if You'll see that gun fix will last longer, I'm ready to deal with those issues by myself, whitch means it's not necessary for You to fix it.