American Express Printed Cancels: Varieties of Subtype F

American Express printed cancel subtype F, with 1900 year date. Each of the seven stamps below has the 1 of 1900 directly underneath the EX. of the AM. EX. CO. portion of the cancel. The stamp immediately below is the "normal" variety of subtype F, with 3 roughly equal size and rectangular periods.

Subtype F with rounded period after "AM".

Subtype F with large period after "AM".

Subtype F with small period after "EX".

Subtype F with square period after "CO".

Subtype F with large rounded period after "CO". General overinking of cancel.

Subype F with large rounded period after "AM" and skeleton period after "CO".