So what's the secret to getting the chrome knobs off the heater control unit? I don't want to break the thing. ('66 Chevelle)

Also, I can't find a repro of the plastic black bezel for the heater control. Mine's in pretty sad shape and I think one of the tabs is busted. Not to mention the little chrome facia is pretty scratched up. Is this a junk yard item?

For the heater control knobs just take a rag and put it over the knob to prevent scratching them grab it with a pair off Channel locks or pliers and do a little wiggling and puling they will come off. I'm not sure if yours is similar to mine on my 69. but I just got a piece of black poster board and traced everything from the old backing to the new poster board and used scissors and a razor blade to cut it out.

you could get a new bezel for your heater panel. i think you get em on groundup.com
check em out