Larry,
A little research in the Chevy Master Parts Catalogs (see screenshot below) shows the rear spring "rear hanger" on the frame is the same part number, GM# 593926 for both driver and passenger sides.
It is also shown to be "forged" instead of cast and has the part number displayed on the piece.
Although the piece isn't reproduced, it is one that Chevy used for
ALL 1/2 Ton trucks from 1937 - 1955.1 (1st Series). That should help open up a little wider search to find a good used one.
I would 2nd Fibonachu's suggestion to contact Steve
KCMongo as I am pretty sure he can help.
