Pilgrim Bulldog rims/tires Combi registration/approval

Hello together, my father and I are currently restoring our Pilgrim Bulldog BJ1989 and would like to drive on spoke rims in the future. I have a good offer for 17 inch spoke rims from Dayton Wheels with cross spokes. Currently, however, only 14 inch wheels are registered. Does anyone happen to have experience with the registration of such rims with the Bulldog? Information such as maximum load capacity etc. are on the rim. Furthermore, we also need hole circle adapters. Company epytec. Does anyone have some experience? I especially liked that I can configure the adapters there completely free, at a reasonably reasonable price, and you also get a TÜV-certificate. Thanks already and dear greetings Phillip