72 carter bbs

I have a purge valve coming In a few days. And tee fitting.
When I refill the charcoal canister with washed media. How do I hold the steel mesh ( 1 4 in. Dia. And 1 smaller. Witch sets on a pedestal and About 1 In. Dia. ) into place? If you refill with charcoal from the bottom ( witch I have the bottom nicely removed). I would assume that the 4 in. Screen is on or near the top of the canister.
I've had my OSAC valve unhooked for 40 years.
I checked the timing, 8" BTDC. The throttle plate is closed. It has a very small opening. I assume just enough for a good mixture.
As before. It resembles the previous schematic. The tank nipple is stopped off because the tank is vented to atmosphere.