I believe what you are going to find is that all the aftermarket wheels are similar. Most have dual lug patterns. In your case it would have 5 x 4 3/4 and 5 x 4 1/2. They are generally called a "smoothy". They are the same as aftermarket "rally" wheels with out the cut outs. The hub cap mounting centers will be smaller than the original but the hub cap can be modified to fit. I got mine from Wheelsmith.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine