Hi Mike,
I have similar rims on my 1927 LM 1 ton truck. The fat, short pin that is the pivot point for the rotating lock was originally just peened onto the rim, not welded.
When one of my pins came off, I put the rotating lock piece on the pin, put the pin back in the hole it came out of on the rim, and had a friend weld the pin back onto the rim. He welded it from the outside of the rim (facing the tire flap), so the rotating part could still rotate.
Here are a couple of pics of a spare rim that I have. I have circled the pin (and backside) that needs to be reattached to the rim.
Cheers, Dean
![[Linked Image from i160.photobucket.com]](http://i160.photobucket.com/albums/t172/stovebltr/Stovebolters/Dean%20Rustoholic%20Meltz%20-%20toys%20and%20projects/temp-pics/1928LM-split-rim-1_zps8gddtjak.jpg)