[Charlie]

That's great... double win with set and tubes! That's a nice H-C! That chassis sure looks easy to rebuild!

Older Motorola knobs are bad about that funky white film as well. You get them cleaned up real good with soapy water and a toothbrush... and a few months later, they need it again!

I wonder... after getting them clean real good, perhaps coating them with some clear spray enamel paint would preserve them. I would try on one of the rear knobs first and see how they look several months later.