i had one damaged the same way and being a welder i thought it would be an easy fix
i made the repair but wasn't happy with the results
so i went with another route
i took a small piece of alum. flat strap and filed it to match the original shape of the ear
i got a drill bit and tap and a couple of machine screws from work(i worked for a gunsmith at the time)
i ground the old ear flush with the grip area of the receiver and drilled and tapped the receiver, then matched the "new" ear with matching countersunk holes
a little bit of black paint and loctite and here is the result
most people don't even notice the repair
i made the repair but wasn't happy with the results
so i went with another route
i took a small piece of alum. flat strap and filed it to match the original shape of the ear
i got a drill bit and tap and a couple of machine screws from work(i worked for a gunsmith at the time)
i ground the old ear flush with the grip area of the receiver and drilled and tapped the receiver, then matched the "new" ear with matching countersunk holes
a little bit of black paint and loctite and here is the result
most people don't even notice the repair