There is a 7.00R15 available that is a radial from Yokohama. Check Tire Rack.
But unless you want to go back to bias ply I have not found a radial "bias" size.
Tire Rack carries a biasply tire in a 7.5R16 from Yokohama Y785R... It says tube on the description, but really I think it is a radial???
Or try this: 700-16 TORNEL LITE TRUCK 6 PLY - Coker Tire
I have some vintage 7.00x16 tires/wheels in the back of my truck right now that are headed to the dump so I know they were made for trucks in that size back in the day. And off of 5-5.5 wheels no less.
For a Spartan in the 40s it came with 7.50x16s. So I plan on switching to 235/85R16-Es.
Hopefully that is possible help. It is hard very hard! I am still stumped on how to get rid of the split rims and make it look right...
I would love to see you wheels setup if you have a picture to share!