I've had this variac laying around for about 40 years - and I know it's older than that. Once I set up my bench, I knew I wanted to have isolated, variable AC, and thought this was a good opportunity to put this to good use. I knew I wanted to show off the variac, so I decided on acrylic top and side panels. The knob was made from a block of decorative wood and spray painted a hammered pewter finish. The volt meter is from Ebay, powered by a canibalized nine volt switch mode wall wart.
The finished build is fed from a Stancore GIS-500 500W isolation transformer, and is tucked back on a shelf on the bench - out of the way, but within easy reach. Downstream from the variac is my dim bulb limiter, rounding out my protected variable AC.