Well, after considering different options about how I might mount my spare tire under the truck bed(and not getting much feedback), I decide that the original design with the hinge was probably the best design.

If I only used bolts hanging from the beds horizontal I-beam to support the weight of a spare tire, it would come crashing down on top of me if I did need the spare.

It seems that the original design of the hinge on the spare tire carrier was important since it would allow the spare tire to slide off the bracket which held it in place.

After searching around and contacting several classic truck part stores , I was told that they weren't aware of anyone reproducing the spare tire carrier for my truck year(54).

I therefore have decided to fabricate a reproduction of the original. I'm half done and will post pictures when it is completed.