Thanks for all the kind words folks, it was a lot of fun getting back to the lathe after a long absence.
Of course the coolest development to come out of all of this was a greatly refined process of how to make the cups. Most of this refinement was a result of buying a Nova chuck and soft jaws which eliminates the need to dill the cups on my press. The drill press was always the weak link in the process and the most frustrating. In fact, between Ian and myself we've got more than just a couple of sets of cups that we'd previous abandoned because we didn't feel like drilling them or the walls were too thin to drill. Given some time I hope to have a go at a few of those and see if they're salvageable and we'll see what happens to them after that. Larry's not going to be pleased...
I've got a small collection of the plastic cups in a drawer. The only metal-cupped ones I've modded have been my own and I've sold the cups afterwards to recoup costs.