Tifosi cassettes?

[UpWrong]

EDIT: I might explore a thin shim between the 2 smallest cogs as you suggest. Guess I ought to also try it cabled up to see if it behaves in the other cogs. Come to think of it, I could try the 8th and 9th cogs from the third Tifosi cassette I have.

OR……you could put the new cassette on the P38 and the old one on the hybrid, as one of them is known to be ok.

I hate robbing Peter to pay Paul. But as a test it would be informative.