Hollander numbers
I'm pretty sure the factory SBP rallyes only came in the 5.5" width and the hollander book only shows one number for the Dart/Valiant SBP rallyes and it's in that width.
There are a couple of places that can custom make SB or BB rallyes in wider widths and in 14" and 15" sizes.Wheel Vintiques is one that I can think of offhand.