Lets talk 1960-1961 cast iron mirror arms

[1963c-10]

I now have 4 different 60-61 solid cast iron mirror arms. Question is Im not sure which ones came on what. I now have 4 different variations. I will include pics. The black one is a short arm, the yellow one with the bend is a long arm for the truck that had the factory spare tire fender, the black one on the yellow mounting plate is a long arm passenger side, and the blue one is a long arm driver. Does anybody know which trucks got the short vs long arm mirrors? I plan to use the passenger side and the spare tire arm. The spare tire mirror is the most interesting as I have never seen another one. The guy I got it from said it was the factory installed mirror on his 60 that came with a spare tire mount fender. I stripped off 4 coats of paint to get it to the original yellow. I was checking to see if its been fabricated in any way, but cant find any evidence of it. Its cast and has never been welded so Id have to think its OEM like the PO said. Being cast, if you tried to bend it, it would snap. Any info on this would be great, as I find very little literature on the mirror arms & I never seen to see any trucks with them. Alot of the older guys around here said that being cast, they broke easy and were replaceed with the hollow tube style started in 62.