Today, Sturdly offered to send me some heatsink extrusion. This will be very helpful in keeping my controller nice and cool. Thanks Sturdly ... it's appreciated!!
I found some hard plastic discs while scrounging through my stuff the other day. I think they are shuffleboard pucks for use on gym floors etc. They are about 10' diameter and 1/2" thick and tough as nails.
More on this in a moment.