Minto. On the Plunger Clutch the first plate into the basket is a slightly thicker plain plate, 67 3240. The small difference in thickness compared to the other plain plates (67 3241, there are 5) is such that it often ends up in the middle of the pack, by mistake. Its function is to support the spring load on the other plates, so a thinner plate at the back here is detrimental to the proper working and set up of the clutch.
Over time the original may have been lost and substituted by the mystery plate. In the short term use this as the first plate, friction side down, smooth side up, or try adding another plain plate if it seems too flimsy alone. Don't mess with the push rod, get the right parts, the correct number of plates and it will work fine, its a good clutch.
Raising the edge of the clutch centre tab washer can be started with a Mole Wrench, then the tab finally flattened against the nut with a drift if necessary. A soft washer and a strong wrist may be enough.
Before assembly, make sure the small split collar and clutch thrust washer are in place on the gearbox mainshaft. Expect a fair amount of rock in the complete clutch, they all do that as the supporting rollers are somewhat narrow and offer relatively little support to the chainwheel, compared to later designs.
Swarfy.
