I experimented a bit this evening and came up with the right length of 1/8" latex for a 25cc bladder, this goes to a 1/8" barbed plastic tubing coupler, and a length of medium silicone to run through the firewall to the engine. The bladder part is housed in a balloon, the neck wrapped around the coupler and secured with a Dubro fuel line clip. A small square of velcro hook secures it to the velcro runner along the fuse belly interior. It is 100% ready to fly. Test glides went fine last weekend. Content with radio installation. Ran a few primes through engine in basement on the 4.1x4.5 toothpick prop. "hey, what the heck are you doing down there??" from the living room directly above. Hee hee.
So tomorrow is supposed to be a bit above freezing, but winds are forecast and rain int he afternoon. I'll pack the airplane to the hangar in case there is a window of opportunity sometime during the day.