Thanks, that's what I kind of figured happened. Is there a specific process for that green colour I should ask the platers to use, do you know?
I have a spare set of rails because I damaged the threads on the ones in my car when I modified my car to suit Recaro's (big mistake) anyway, I will tap and die the threads back to good and then send off the rails for replating because I bought another pair of rails years ago (for $100) from the US but they were a bit rusty/messy looking at since I installed the Ikeda Bussan seats the rails are a lot more exposed and look crap, where as the stock seats would cover them more from view.
I have a couple of spare 280zx distributors here, I couldn't find them at the time otherwise I would have had all of them restored also. So maybe I can offer people an exchange service? Sounds like yours have been nicely done. I was in the process of doing that kind of plating for my '240z' points distributors, but the shaft was stuck in the housing and no amount of heat seemed to free it.