Good luck with your search.
I had some original G503 combat rims sandblasted recently - they are a 50/50 judgement call if they are safe to use. Just be aware the originals are now around 80 years old and they do suffer from chronic rust and abuse. The rust typically attacks the 90 degree middle flange corners where the divided rims join. Many of the G503 restorers now use the Juan repro rims and the rims seem to be fine. There was another brand of very unsafe repro rims so be careful.
Having written all that, I've never seen an original rim have a major fracture and come apart. In my case, my rims have corrosion eaten down to about 50% of the original steel on the centre flange corners.... it just looks unsafe to me.
If you drive to the local shops doing 35 MPH ..... it's probably OK but doing 50 MPH on a busy highway ....
The other very common issue is: people over tightening the lug nuts, this distorts the holes badly, so much that the rim isn't sitting firmly on the drum. The original lug nuts are 3/4" across . Early Chrysler Valiant/Plymouth cars have the same nuts in LH and RH thread.