Hi Mick, you remove the dissy spindle from the housing unit, the bottom plate that has the three pronged unit which presses the lower plate up can be disassembled by removing a small spring collar that fits snugly underneath it holding it in place. You then grind off the two small pin heads which secure the two top halves together leaving the lower side of the plate smooth. I am going to make the almnm disc/plate to take the place of the plastic unit that was originally fitted except it is going to be slightly smaller in diameter ,hence the four ball bearing supports instead of the usual three. I'm going to drill a lot of small holes in the almnm plate to lghtn it off as much as possible. Will be a bit of trial & error but I'm sure I can get it to work.Will post some pics when I get around to doing this. Might point out Mick that there is anthr post on dissys with some very good info.
Regards: Alan.