I am not really sure whether he welded it with an arc welder or TIG MIG welding. I remember him telling me he used black iron rod. He once used a nickel or stainless alloy rod and NO JOY at all on it. HUB is on this forum and he makes BABY LUGERs he would be the one to ask, his welds always rust blue great and match the grip straps. That was 7 years ago and I am an old toot so I dont remember all the details after all these LOOGERS!
PS I think Don did some kind of low temp welding because he was afraid there was not much metal left on the grip strap. That is also a concern where the metal is thin.