Ok folks, update.
Tonight, I had a REAL mity vac and did all of the testing with that.
I replaced the following vac lines: from big vac line (from vac pump to booster) to tee 1, tee 1 to tee 2, tee 2 to ASV, tee 1 to check valve, check valve to tee 1a, tee 1a to n75 valve, from tee 2 to n18...