That almost looks good to me, Denny.
"Second, the 1/2 ton trucks, whether Hydra-Matic, 3sp.or 4sp manual, had a rear transmission support and were enclosed drive shaft up to and including 1954."- Only the 1/2 ton Hydra-Matic 1954 trucks had a rear transmission support. All other 1954 1/2 ton trucks (with manual transmissions) had
no rear transmission mount (a rear transmission mount was used on
earlier 1/2 ton Advance-Design trucks).
Questions:
"First off lets correct this, the Hydra-Matic was first offered in the 1954 Chevrolet model year trucks, not before then."- Why did you state this - did someone post something different?
"I also cannot confirm whether the 3105 rear transmission mount and cross member are the same as the 3104. From what little information I've seen, they appear to be the same."- What would cause you to doubt this? panel vs pickup?
This post might be boring to non H-M members. It has been a good exercise for those of us who like to see/know the facts/documentation, before we start to speculate on the gaps in the documentation.