...So, today I disassembled the old pump just for giggles. Note
that there is a number, 829, stamped into the frame:
Looks like the older pump was manufactured on the 82 day of
1989.
My old pump is still going strong with no adverse
operations. It is a 1987 dated pump (#1427). The only
teething problems I had in the beginning were the VEP pressure
switches which caused me to burn out a gear pump relay (I replaced both
relays). I did send the pump to Oildyne in the first year of
flight for their valve upgrades.