I've never had a problem with the Luscombe I've flown a couple times within the 30nm mode c ring of a class B airport. Then again, it doesn't have an electrical system. I had a guy fly an aircraft with no transponder, and no radio for that matter into STL a few years ago for fuel at my FBO. A couple phone calls and he had the approvals he needed.

Also, a transponder is required in and above Class C but not under the shelf.

As for the boss, I think he owe's you a 12er. Everything I've found on SAT states it's class C. I don't have a sectional or AFD but it looks like the tower is 24/7 as well.