Hi, and sorry to be a late-comer to this most excellent thread. I ran across it looking for something totally different, but thought I might have something to contribute.
The red plate over the AE-35 unit might not be a permanent piece of the device, but an overlay used to isolate and identify test points. (then again, it might be permanently mounted but still serving the same purpose) But if it is a temporary overlay, it would explain why it is seen oriented both ways, possibly by accident, such as upside-down in the B&W Getty image. I think as a prop item it is meant to have the lettering right-side-up when facing the camera.
That aside, I have a possible interpretation of some of the text. At the top, it possibly reads
A.E. BORESIGHT ADV.
AE 35 MOD C
CONTROL UNIT
"Boresight" being the term used to aim a highly-directional antenna at a very distant receiver, which of course is what the AE-35 unit does. I'm not certain of the ADV, but it looks like that and could of course be short for "advanced"
At the bottom, it possibly reads
EQP. CHECK OUT
MOD. L.A. 375
But the last line really eludes me. The second line could also read "MOD. L.A. JPL" as a nod to the Jet Propulsion Lab. The "EQP. CHECK OUT" line is what suggests to me that this is an overlay used for testing the device and is removed before putting into service - "Equipment Check Out" (it could also be "EQT." but I think "EQP." is the more common abbreviation for "equipment")
The rest of the markings are likely just random stuff to supposedly represent circuit segments or test points, and good luck figuring out the numbers and letters. With one exception (or actually three): There are several dotted circles, three of which have 3 letters inside, two of which have holes with the letters as well. I suggest that C, B, and E are the three letters, which stand for the Collector, Base, and Emitter of transistors. In the 1960s, integrated circuits were nearly non-existent with transistors being the high-tech of the day, and they were commonly in small round packages with the three leads arranged in a triangle, such as the markings on this plate.
Oh, and my money would be on the font being Futura, which was extensively used by NASA at the time.
Anyway, my 1.5 cents worth (adjusted for inflation). Maybe it will be of use to someone here.