This thread exhibits a common misunderstanding of nomenclature.
First, there is NO Pilot Operating Handbook for a Piper PA-12.
Second, the booklet that Brandsman posted a picture of is the "Operating Handbook" or "Owners Manual", or whatever. Tells you basic information on how to take care of your airplane. This document is typically NOT required to be aboard the airplane for flight ops. Univair is a common supplier of these.
Third, for many (but not all) airplanes build before the mid 1970's, there is another document which IS required to be aboard the aircraft for flight. This document is called a "Airplane Flight Manual", and was issued to that particular aircraft serial number. Typically, the manufacturer of the airplane is the only one who can issue a new or replacement Airplane Flight Manual. That said, many of these documents were virtually identical between examples of the same model.
When I purchased my 1952 Cessna 170, the Airplane Flight Manual was in tatters, and virtually unreadable. I contacted Cessna, who referred me to their supplier, I gave them the serial number of my airplane, and the four page "Airplane Flight Manual" arrived in the mail a few days later, complete with my serial number.
Here's a link to the PA-12 Type Certificate:
https://www.cubclub.org/tc/Piper/A780.PA-12.pdf
Scroll down to item 401, and you'll find the requirement for an Airplane Flight Manual:
401.One of the following CAA (FAA) Approved Airplane Flight Manuals revised to include any statement required under
"Propellers and Propeller Accessories" and/or Item 103, if applicable.
(a)Airplane Flight Manual dated March 24, 1947, or Piper Report No. 551 dated
March 24, 1947 - includes Propeller Item 1 and O-235-C engine.
(b)Piper Report No. 570 dated April 15, 1947, includes Propeller Item 3 and O-235-C engine.
(c)Piper Report No. 565 dated June 13, 1947, includes Propeller Item 1 and Item 103.
(d)Piper Report No. 571 dated June 13, 1947, includes Propeller Item 3 and Item 103.
(e)Edo Report No. 2342 dated April 10, 1947, revised January 11, 1949, includes
Propeller Item 1, O-235-C engine and Item 204.
*(f)Supplement to Flight manual dated April 20, 1955 (Required with Item 403 Ross Control System)
And, note in the case of the 12, the Flight Manuals are specific to propeller installed, and Supplements.
Many modifications for aircraft come with a "Airplane Flight Manual Supplement", which also MUST be aboard the aircraft during flight.
To add a bit of confusion, some airplanes built prior to the 1970s, when standardization of "Flight Manuals" into the now required "Pilot Operating Handbook" (which didn't exist in the late 1940s) were never issued an Airplane Flight Manual by the manufacturer. For example, my 1958 Cessna 175 has no requirement for an Airplane Flight Manual, according to the TC. BUT, several modifications came with a required "Airplane Flight Manual Supplement", which DOES have to be aboard the plane when it's in flight to be legal. So, no AFM, but an AFM Supplement has to be aboard. Go figure.
So, it helps to use specific nomenclature as to which document you actually need.
MTV