If you want the GEM vintage blade experience, I suggest using current production GEM carbon steel blades. The PAL Blue Carbon are the best and longest lasting. The Blue Stars (also sold under store labels) are a step down.
With the GEM stainless PTFE coated, I cork the blade before first use to smooth it out.
The Micromatic Monday thread is a major GEM / ASR razor hangout. Great source for fine points, too, if you have time to scan through. Shimming is a hot topic currently.