Guess I'm about 15 years to late. Were living in the age of dripping venturis now.
Sorry, just saw this. Yeah, I was a BruLine user myself... and when they started to disappear off the shelf, i stocked up, only to find what you found. All the one's I bought were people just unloading old stock and the filters were brittle and chemically breaking down already...
But take heart, there is a simple solution, and maybe a bit of a BETTER tuning feature for a silver lining. Buy a bag of assorted rubber O-rings, and beg borrow or steal a pair of your significant others panty hose. Cut them into appropriate size shape rounds and put on 1/2/3 etc layers as you see fit and use the o-ring to hold in place. It really lets you dial in your run, and keeps the dirt out and drips in.
I looked at a LOT of other R/C Nitro car filters on line, but most looked too tall or unwieldy for cowl installs, plus were mostly made for smallish .12 -25 'ish size engines... I didn't feel like having to buy one of each until I found something that worked, so settled on the old panty hose trick.
YMMV, and that's a feature, not a bug!

EricV