Marek loaned me a #21 filter last night and it helped.
I basically wrote off getting one a while ago, but
it turned out they were indeed in stock locally.
(oops.)
Anyhow, if anyone has a source, or has one, let me know.
The orion store is not answering the phone these days, and
I probably wont make it down there anytime soon just
to check.. (though if someone happens to know if they
have a bundle of them in stock, I'd make the trip to
get one.)
thanks
jeff