True Westinghouse
It's easy to tell if they have the old logo.
Westinghouse was such a diverse conglomerate at the time of the sale to White Consolidated that WCI was not allowed the rights to brand under the Circle-W logo and as "Westinghouse." Hence, the doubled-W, "White-Westinghouse" brand was born.
The early entrants were very much the same thing as the true Westinghouse product, but over time, evolved. Kind of like Frankenstein.
So, if it says "Westinghouse," you really can be sure.