I have two new SS212 wheels in 4x137 pattern 5+2. Never used them. Going a different route. 12x7" wheels. There are a few ways to make these work on your XX.
Adapters is one way. If you use them on the rear a set of stock hubs could be modded to fit the pattern, I saw one guy on ebay sold an XX with 12" ss wheels. He didn't have hubs or adapters but these same 137 patterns drilled out a bit to fit. Only off by 7mm. That's just a hair over 1/4". I think it could be done just changed my mind and going a different route.
100 plus shipping. I will also powdercoat them anyway you want them.
Here's some good tire's one could use with them also.