Well, in this case I am grandfather.
My dad and I collected stamps when I was in grade school (1930-1936). We collected blocks of 4. I have not looked at them for over 40 years. As I remember some of the unusual stamps came in a different format than the sheets.
I have 1/4 cent (McKinley as I remember) and 50 cent airmail (Remember, at that time you could buy a new Chevy for under 2,000. 50 cents was serious money).
The postmaster at Guasti or was it Alta Loma would call dad if any unusual stamps appeared. We would go out and buy some of them. The population of Guasti or Alta Loma was probably well under 500 so it was a "Folksy" post office.
At one time Guasti was the number one place in the nation for murders per capita. I guess one murder every few years could put you in that category if your population was small enough.
Guasti and Alta Loma were both located in the largest wine vineyard in the world at that time. Now they are both in the middle houses, malls, schools, etc.
First of all you have to be smarter than the machine.