Good to know about Allspars, since they are quite local to me. Z-spars had all the parts I needed. They have a good stock of pre-2000 Z-spar mast spares, though they will run out eventually.
One of the annoying features of the mast is the mastgate that has to be closed for the sail sliders to run up and down the mast. The screw that holds mine in place when closed has worked loose. The solution has been to screw self tapping screws of increasing sizes through the gate into the mast. But that solution has reached its limit with an M6 (I think it was) self tapper.
The solution suggested by Z-Spars is to use a Rivnut - something I hadn't heard of before. I'll see if it works. I wonder if others have had the same problem?
Jake