Vintage Simmons Drums (UK) Users Group

Im am trying to replace the little white trim pots on some of my SDS 5 
cards.

from what I can see each preset has 5 beckman 62P R100K 8333S and 1 
Beckman 62P 1 meg 8321S

I have found some various trimmers in catalogs,  and one worked OK,  
but was a bit out of line with the hole on the front panel.  another 
type although they kind of fitted (bit too big) and they said they 
were 100K didn't work at all.

can the Simmons Tech Guru's point me to a source of the correct 
type's,  or even just some pointers on what I'm looking for.