A couple answers:
The rag joint on my 54 is a flexible rubber unit. On another 54 I had, it looked more like a tire cross section. Both were factory units so there must have been a running change. They are not commercially available, however, there may be another car with something close. A used unit may be your only recourse.
You will need the key to remove the lock cylinder. The key sets the pins to level and allows the cylinder's removal. With the key inserted and turned, look for a very small hole in the housing - insert a stiff wire in the hole, a paper clips works best, and push in while pulling back on the key. This moves the lock ring out of the way and allows the cylinder to slide out.
