This is serial # 752 indicating it was built in 1952.
For you Collins collectors, I'm afraid that it's been modified a bit by me in my
reckless youth.
The 6BE6 BFO has been made into a product detector.
The crystal filter has been removed and mechanical filters are in it's place.
The little toggle switch about the S-meter changes the AGC time constant.
More info on the 75A-2 at "Boat Anchors"