This one is kind of hard to explain, but it's really cool and going to be a big help for us calibrating these machines in the sweaty dark.
If you don't have access to spare audio parts this might be kind of a stretch but, I thought I'd mention it anyway since calibrating tape machines aren't exactly the most enjoyable process.
My neighborhood tech made an awesome replacement for the generic calibration pic. Instead of fishing around for the coil groove, it just slides on like a glove.
He took a common mini green flathead screwdriver that you can buy at a radio parts store. He then took a standout nut used to brace pc boards and whacked the screwdriver into the nut. It was a kind of rounded-edged bronze colored standout nut, so the coil just slides right onto it. no B.S.
We're seriously stoked.
Highly recommended rig for somebody pulling their hair out during cal in less that optimal conditions.