it says "C.P. GOERZ AM. OPT. CO." serial is 813277
Well, that helps narrow it down. Your lens was made around 1963 - give or take a year. I don't have a Goerz serial number list for that time period, but I do have some anecdotal and circumstantial evidence that helps narrow it down.
Sometime between May and December 1964, the company name was changed and they started labeling their lenses GOERZ OPTICAL CO. INC. to reflect this change. I have a price list dated May, 1964 that still lists the company name as C.P. Goerz American Optical Company, and another dated December 1964 that lists the company name as Goerz Oprical Company, Inc. So, that establishes the upward bound as 1964 for your lens.
On the other end, I once had a 4 3/8" WA Dagor with an 803xxx serial number that was part of a 4x5 camera kit that was originally property of the US military. Included in the case with the camera (a 4x5 Burke & James monorail) and lenses (the WA Dagor and a couple of Ilex tessar-types) was a copy of the original purchase order dated July 1, 1961. Of course that date always sticks in my mind as the birth date of such luminaries as the late Princess Diana, track star Carl Lewis and, of course, your truly.
Kerry Thalmann
Really Big Cameras