As I recall (having lived through it and as a kid being interested) Muntz was a pre-WW2 era company who went into consumer goods around 1950, our 23" B&W came about 1952.
I first remember Silvertone as a label used by Sears for their product line about the same time. I never encountered a Firestone, they were primarily an OEM and independent dealer-based company in my area-the first company store opened around 1970. I had a relative who worked for Philco who remembered making radios under various private label names over the years long before Ford’s 1960s acquisition of Philco.
I remember seeing billboards in the 1950s which said “Stop Staring at Your Radio… Get a Muntz TV”
From the 1930s till the 1960s Firestone was a retailer and had multiple manufacturers like Stewart Warner and Emerson supply their brand-named products.
I certainly remember Firestone, just not for consumer electronics. I owned their tires and they sponsored major auto racing (Indy 500?) My family was in the tire business, three of us were at the LEE Tire plant before Goodyear bought it. Here in suburban Philadelphia, I just never saw a Firestone store until the '70s - they sold through independent dealers, right alongside other brands. My '68 Firebird came from the factory with the Firestone “Wide Oval” tire and I had to order a replacement through a local tire guy because there were no direct consumer outlets.
