I was wandering around the local JY, looking for Bonneville seats, and did not find any good ones. But I discovered a source for OCC horn buttons. The horn buttons on the 90-93 (may be a couple more years) Cutlass are the same as the OCC. I pulled a couple of excellent sets, one in red and one in gray.
I also found an full size top of the line Olds sedan (early-mid 90s) with horn buttons that have the radio, and heater controls on them, which will fit the OCC airbag space. You can swap out the airbag or the whole steering wheel. You will need the wiring for the controls too. I did not pull them, because they were broken, but they were very interesting. They looked similar to the regular OCC horn buttons with extra buttons below a shortened horn button.