[Johnson] Ranger VFO help

[K6JEK]

I could use some Ranger VFO advice.   The VFO puts out a nasty, raspy 
signal, quite audible on the final signal and ugly on the scope.  With 
a crystal, the signal is nice and clean.    I haven't really torn into 
it because, gosh, it's not easy to access.   I did try a couple of 
different 6AU6's and a different OA2.    The infamous 18K is long since 
replaced.  The also suspect bias electrolytics, C90a,b, have also been 
replaced (maybe I should change them again) and the keyer adjustment 
doesn't  make it better.

Any ideas on how I should go about finding this problem?

Incidentally, I thought I'd gather up a few parts so that when I do 
open the VFO completely, I'd have  replacement parts on hand. Fat 
chance.  The Ranger VFO is full of things like  91 pF +- 2.5% N080 
500V.  I sure don't have stuff like that in my junk box.  And what does 
"mica D.char" mean anyway?

Jon, K6JEK