The first letter in the serial number is “A”.
The grease in the headset was so gummy that it effectively kept the bearings from moving; the grease in the front hub was- wait for it- nonexistent! No wonder it felt a bit rough!

I think the only original parts left on this were the wheels, Campy headset and front derailleur
I think I have a set of Campy downtube shifters and correctly sized seatpost rattling around in the parts bin.
Yes, the original owner got busy with his drill on the rear Suntour derailleur and rear brake caliper. Thankfully he stopped there!