It depends on what clutch is fitted to a 750K. They got better and evolved as they went on up to the K6 with double plate.
The main mistake is using old clutch plates that measure within spec but are as hard as nails.
You could have two different types of plates fitted to a 1975 K2. The outside plate could be slanted or straight groves. You will not know until you get it apart. We have never had a problem with the K2 clutch, they are smooth but all clunk a little when selecting first gear.
Not sure why your K2 is dressed like a american K2 when it is a UK model.
