Staco Energy model 201 small variac. Rated 120v input with a 2 amp output. Has extra terminals for connecting as a standard 0 to 120v output or 0 to 130v output — ie: extra windings for boost output. We often see these small variacs priced very high on eBay ($50 or more). Sell here $10.
This one sold — there are two or three more at Gordon’s.