Starting here a running account of my "new" Altec A7-500s
I'll document my findings and the work I do one them. I've been wanting a pair of A7 or A5 speakers for many year, now thank to forum member "old Guy", I have a pair. And at a very reasonable price, too!

These belonged to a fellow who ran a music store in Ohio.

Here's what I got (see photos below).

825 cabinets (I think) in 3/4" ply. Looks like A/C grade, lots of knot holes on the inside. But pretty solid and in nice shape. They have been taken care off.

416-8A drivers in the 16" frame. Don't know if they have been reconed. It looks like the cabs had 15" woofer originally, as the bolt circle is so small that it just barely fits the 16" cast frames. There is window screen in front of the 416s, as you can see in the photo. Don't know if it's to keep bugs out or beer bottles!

On top of the cabs, bolted on, are the horn houses. More 3/4" ply with a 511 horn + 802-8 ohm driver. The 802s have the symbiotic diagrams and loading caps. They appear to be from 1971. I've never seen the horn house before, Todd W says they may be from the 50s.

Crossovers are the stock N-501-8A type. Nominal 500Hz, 2-way with L-Pad on the HF side. I will post schematics and photos later.

OG said that one of the compressions drivers was bad, but it turned out to be an easy fix. The spade terminals were touching the inside of the back cover causing a short. Bent them down and it works!

So I have a fully working pair of A7-500s. Yeah!