The first tear-down from this lot. A HP 3480B, made in 1970 last calibrated by HP themselves in 1972.
The unit itself was at least calibrated in 1972, no definitive data on this part. Not the same plug in necessarily. Sorry for the delay on part two, sick as a dog and had to get a different plug in out, not going to dissect the best one.
I'm sure this part will interest at least some of your more, this is where the magical pixies live after all.
Bottom rear.
Bottom front.
Top front with covers in place.
Top rear with covers in place.
Top front with covers off.
Top rear with covers off.
Nice as it all looks this is all so sensitive that even touching it could affect accuracy, so they say anyway. Fingerprints, other dirt and contaminates are evil as the outer cover says.