I know I have asked this before but thought I'd ask again.... does anyone have a really decent, unworn clutch centre plate/centre with decent unworn splines. This has to be the longer type splined register without master spline for a 1930 gearbox.

best,

Nick

If the female spline in the gearbox has a master spline then the spline on the centre plate has must have one too. If it doesn't either male spline will go in.
However the length difference is important.
On my 1929 car I was using a later 'master splined' centre plate and it always dragged a bit. I recently changed this for the earlier, shorter centre plate without master spline. The clutch now disengages cleanly.
I think the tolerance on length is quite tight and that the longer one was bottoming in the gearbox.
I don't know when the length was changed and my gearbox is made up of parts from more than one. Most parts are interchangeable on 3-speed boxes, but the 1st motion shaft with the female spline comes in more than 1 type.