I'm not confused.

Altec didn't build a production 12 inch speaker until 1948-1949.

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A bit more: http://www.voiceofthetheatre.com/ima...02C.605A.2.jpg - 601c 12-1/2 inches.
601C is late in the game, white painted frame. There were "A" and "B" versions too. They all came after the introduction of the 3000 tweeter, 1950's stuff.