I just got a pair of these:
15 X 6 (6 bolt on 5.5") Black OEM style wheel for use with Baby Moon hub caps.
0 offset, 3.65 pilot, rated at 2,600# at 75 PSI
15 X 6 655 Black OEM style wheel for use with Baby Moon Hub Caps
They fit my 1965
Safari perfectly. They don't have clips for the old style hubcaps but there are newer versions of the Baby Moons that will fit.
Although they were out of stock at Traile tires and wheels.
The 3.65" center hole was the same as the old split rims I took off.
The wheels are USA made, trailer specific wheels by Dexter Wheel Company. I suspect that the wheels that Vintage Trailer Supply and Inland RV also come Dexter.
I saw a post by someone else that got wheels from these guys, so I gave them a try, seems like a good outfit.