There are such devices, although they would not have been around in the 50s. More than likely a lightbulb fixture was screwed onto the inside of the shell. The lights weren't just used to make the head look pretty, it had a function. Calf heads can vary pretty drastically depending on the weather and humidity, warming the head kept the skin tight and would eliminate the need to constantly be re tuning. I've seen plenty of snares with homemade heating devices, maybe 1 or 2 with an actual marketed heating element for a drum.

I knew they were around much earlier ( pre WW2 ), but also never thought Slingerland had made one ( thought they may have as well ).