G'day Widget,
Yep, there should be single gaskets at both ends of the barrel. Cardboard [cereal packet!] will do for the base gasket, but the head gasket is a heat-resistant composite material that's not easy to find in sheet form. For the whole $1.43 the ODK Shop list it for, just buy it; you'll need to buy the exhaust 'ring gasket' anyway.
As for testing of the condenser, some higher-end multimeters can test for capacitance. But the job really needs to test for leakage and series resistance as well, and that's a task for a dedicated condenser tester.
Mower shops once had these testers, often combined with a coil tester, but I doubt you'd find one easily now [tho' my motorcycle mechanic still has one].
