Drove across town today on my lunch hour to a counter top business. This old guy, probably been selling Formica since it was invented, greeted me and when I handed him the original gauge panel he looked at it for about 5 seconds and says " looks like a 343 to me." The man knows his Formica because the sheet he brought out is a perfect match even after 33 years.
I used some sheet metal shears cut out the traced pattern from the original. It was a tad bit larger but with some sanding on the belt sander it looks and fits perfect. I'm going to back it with some 1/8" ply to make it a bit stronger. I'll have to leave about 3/4" of a Formica border and I'll use 3M trim tape instead of the silicone and pop rivets originally used.
A 4 x 3 sheet was only $15 and I can squeeze out four of these panels. Anyone need one?
