You're welcome! I see I forgot to post the nice Altec site I got them from:

http://www.voiceofthetheatre.com/

Note on the horn selection/pricing sheet the '800' system [original A7-8] listing, though apparently not in the catalog. It's been suggested that it didn't arrive until the late '40s, with the downsized A5, A6 shortly after:

800 VOTT

ALTEC speaker Systems

I guess in a bid to capture as much of the post war market as practical, they initially offered a large variety of big, expensive systems, but the rapid rise of union labor costs and the sprawl of the new ?suburbia? with its desire for small neighborhood cinemas quickly forced a shift to a smaller/cheaper product line. The large A6 [minus its baffle stand] at my high school came from the late ?50s closing of just such a local strip mall cinema due to expanding to a Cineplex where even the downsized A7 series was overkill, peak sound power wise.

GM