I had the guage cluster totally cleaned up and repainted (with SEM). THat all worked out great. Hornets have a black-masked lucite insert, "HEADLIGHTS" "WIPERS", the paint flakes off, so I scrubbed it up, refilled the black, then mounted it with I believe silicone rubber (doesn't need a lot of strength). That was almost a year ago. It's installed in the car, and I've had a clean towel over the dash.
Well doing interior work, I removed the towel, and the entire corner of the gauge cluster has melted! In a running car I'd assume it was a hot bulb -- this car has never had a battery in it, ever. It's not in the sun; the car is plastic-covered, and had a towel over the dash. Nothing else is harmed, at all. ALl the damage is restricted to the lower left corner, and the lucite insert. Hell, the nose of the car is facing south, it doesn't ever get direct sunlight at all!
It's got to be solvent-creep from the glue job (that sounds vaguely obscene... :-) I'll find out when I extract it for replacement.
I may have used red silicone (RTV), the red hi-temp gasket stuff. It's clearly the wrong silicone for the job, but it's not visible, and strength was no issue, it may outgas or something.