[GreenKeys] Red paint on Teletypes...

[Jim Haynes]

The original Glyptol was a G.E. product.  Blue Glyptol was the thread
locking stuff, and red glyptol was the inspection mark stuff.  If you've
ever taken apart a BC-375 transmitter or one of the TU-xx tuning units
for it you've encountered blue Glyptol.

So far as I know Teletype Corp. never used either kind of Glyptol.  For
thread locking they used lock washers - it was understood that you didn't
want to make disassembling hard, since you might have to replace parts.
Unlike the BC-375 which was intended for use in airplanes with lots of
vibration and you didn't want anything coming apart in flight.