Looked it over and this unit was in the original box and packing and appears to be in mint condition. No signs of wear, no scratches. This radio is widely considered to be the state of the art design in 1955 with the highest quality and latest design features that  make it still one of the highest quality receivers ever made.
 

Ordered the instruction manual and a book of upgrades and service bulletins
This radio employs several Collins innovations including mechanical filters and permeability tuned oscillators. My recommendations for further restoration include such standard items as replacing the "7 black-death caps" and the three "heartbreaker" micas. I'd also put in the AGC, product detector, and audio mods. These are standard mods for all 75A-4's.

Initial power up using a variac showed no problems, no smoke and even had a bit of static from the speaker. This will be a winter project to restore it to full operation.
Check this radio works link for more on the 75A4

We also received three more ancient radios in great shape
Here's a 32G-16 Transmitter
Introduced in 1936, the 32G was a celebration of the "6L6" tube
It used eight and was marketed as a general purpose amateur and commercial transmitter ...more

32V2 Transmitter
A companion for the receiver above
 

Radio Receiving Set AN/ARR-7 is an airborne search receiver intended to locate enemy radar radio Frequency channels and communications equipment operating in the frequency range 0.55 to 42 megacycles. This receiver is designed to be used with equipment which will indicate visually and aurally the presence and character of received signals over a pre-determined sector of a given tuning band..

R-R-45/ARR-7
Not sure what we'll do with it but any electronic countermeasures equipment from WW2 is a find. We'll put this on the back shelf for now..