I haven't owned a Kontrapunkt B but I do have an A somewhere which doesn't work well on the FR64fx, it was much better on my Graham 2.2 though not a cartridge I liked very much. I think that the FR64fx is also too heavy for the two MM's and indeed the ZYX. It should have worked well with the Decca though, provided you had a nice heavy headshell.

If you want to try my tonearm cable to rule that out as a problem I'll happily lend it to you for a few days next week - it's probably time I had a listen to the Graham again!