Thank you, Vince! Following your lead, I see that it's also called the seven-bar circular grid.
Further searching got me to a comprehensive display of Scott #1 cancels, including this goofy one:
These were pretty common during the period with some variation (below). I have seen ones in red also. I don't find many (any?) in use after the mid 1860s.
Is there a generally-accepted name for what looks like a fairly common cancel? If not, I hereby christen it Manhole Cover!
Coincidentally, the German catalog Michel catalog uses the same design to identify cancelled-to-order stamps.
I bought this 1860s cover because it shows two post offices which later changed their names: Hooker to Whitehall, and Portage City to just plain Portage.
re: Is there a name for this style of killer cancellation?
Thank you, Vince! Following your lead, I see that it's also called the seven-bar circular grid.
Further searching got me to a comprehensive display of Scott #1 cancels, including this goofy one:
re: Is there a name for this style of killer cancellation?
These were pretty common during the period with some variation (below). I have seen ones in red also. I don't find many (any?) in use after the mid 1860s.