Was going through a few letters//cards, etc....
I noticed that standardized cancel machines/hand cancels do not follow a process of keeping what the postal locations use as a standard cancel.
After just looking through
ONLY 39 cards from just one area (
Fort Erie) and narrowing it down to just
1976-1977 time frame...I noticed that the 2-3 Postal locations used at least
7-8 different cancellation devices/stamps...Here a few below, and remember, this is only from 39 cards/letters.etc.



And here is one card with 2 different cancels on it.

Not earth shattering, but interesting to some collectors.
Any opinions..Robert