Today I made up a little break out / control box for my variac using parts I had in the workshop. There is nothing in the circuitry, I had a cheap chinese 300VAC meter movement left over from another job, these are surprisingly good quality and very cheap, this wired direct to the output of the variac before the switch, so a voltage can be set before applying power. The neon was probably not worth bothering with, especially as I didn't check it and fitted a 24V bulb, it lit once. The 4mm sockets can be used to insert a lamp limiter or ammeter, but I've ordered a 5A meter and will fit it in the hole I cut once it arrives and is cleaned. The whole lot fits in an electrical junction box screwed onto a wooden base along with the variac. A couple of hours effort makes the variac a much easier to use.
Here's mine circa 1987 ish...
Here is the final result with the meter fitted, new neon and better knob.
Those Chinese meter movements are really good value, it arrived really quickly, the packaging was disposed of and meter cleaned of course. They look really robust and I've bought a few, they aren't very well packed but all have arrived intact and working, they also have a nice vintage look and seem accurate enough for indications purposes.
Hi Tony, Yes I will try that, I used a Q-max cutter for a nice clean cut. Unfortunately since I started this thread my variac has bitten the dust ! The brush failed and caused the winding to go open circuit at the point of contact. Variac brushes and old variacs seem to be very expensive however there are cheap Chinese units but I'm unsure of the quality of these. So at the moment the box is just used as a lamp limiter.