I have two unused M70-AB2 kits from CFS I'm building on DCI receivers.  One of the mag catches is set further back in the trigger guard than the other one and the mag wobbles up and down which could cause feeding problems.

I called CFS and they will do an even swap but I have to send the underfolder in also because they don't have any disassembled.  I don't want to do that and get a used one back and have to go through taking that one apart etc.

Any suggestions?  Egg the four holes to move it toward the trunion?  Any leads on spare trigger guard/mag catches?  Welding a bump on it would be ugly and I don't have a welder.

I think if I had some really nice kits like you do I would buy a new trigger guard and do it right.
An alternative solution would be to buy another pin, remove the old mag catch and either put a tack weld on the end or you could use a small piece of steel and silver solder an extension on from the inside. Once you have the mag catch out you could easily take it to a muffler shop and have them do a quicky weld. The pin is an easy install you just smash it in a vice.