Attached a pic of the cleaned and installed screen- looks like a good fit but it will sag about 1/4" along the back edge after a few heat cycles. I vacuumed the cat off, and used a vinegar /water mix sprayed through the cat, and then rinsed it with distilled water. (this was suggested by Woodstock, as the PH cat is too long to boil in a pan). Fired up the stove and it is burning good and the cat seems to be working... no smoke out the stack but I did notice the top of the stack is pretty dirty- suggesting the cat has not been doing it's job during previous burns... I guess for now I'll just have to clean both the cat and screen about every two weeks... My flue set up is straight out the back of the stove, thru wall to a tee, then staight up 18' (or is it 21') enclosed in a insulated chase except for the top ~4'. Flue pipe is Class A 6" Selkirk supervent insulated double wall, with a short section of double wall connecter from stove to class A.