[C320-list] Stainless cylinders covering bronze shroud turnbuckles

[RUTHE SMALL]

I have a  94 Hull 320 #74--RUTHSM.  Since I bought the boat a year and a half ago I have been attempting to loosen the stainless cylinders over the bronze turnbuckles on the shrouds so I can check the turnbuckles and tune the shrouds.   I have consulted two different riggers, tried liquid wrench, talked to Catalina, so far to no avail.

Now I'm going to the big brains out there.  Has anyone else encountered this problem?  And more important, has any one solved it?  and if so how?

Thanks
Sam and Ruthie Wagner