Dudley, I am curious if there is any "shadow" left on the neck of the P/s pump from some kind of a cover used to keep paint out of the pump when it was painted. Your car pretty much proves that the dipstick was unpainted unless you find traces of the paint on the dipstick because the paint did not stick to the plating. Thanks for posting the image and checking on the shadow.
There is no shadow on the fill neck. There is no trace of paint on the dip stick. I took pictures to illustrate.
Below are both the fill neck and the dipstick. I could not get a full read of the part number of the pump
with the hose bracket in place. The only digits I could see looks to be 8F 10B on what looks like could be an ID tag
held in place under the hose bracket. Looking at the back of the
pump, there looks to be a stamped rectangle with rounded corners in the 10:00 o'clock position, but I can't make out what the wording
is inside the rectangle. There also seems to be what looks like a serial number stamped into the pump body.