An example of four Farberware heat probe temp controls for their electric appliances... "Perfect Heat"... from left to right... an early 1955 Leviton - no model number... an early Leviton model 100 - note the 1950s TV style dial in gold white black... a Leviton model 100 with gold sticker/lable - very common version... the later model 101.
All four are listed as New York, USA... in later years the 101 model was often marked China or Mexico.