Motor Sizing and Wiring Diagram Help? My motor has a wiring diagram but no ID tag
"Farm duty" motors and 9-lead motors are common in the USA. As is common with new users, you have neglected to indicate the part of the world in which the motor was found, but the label says made in USA.  Since 120-volt, three phase motors are practically non-existent and 240/480 volt 3-phase, 60 Hz, 9-lead motors are quite common in the USA, I suspect that is what you have. If none of the leads are marked, you will have a really difficult time determine which leads are which, but there may be a procedure somewhere on the internet. Google "identify leads of 9-lead motor" or something like that.

To find the horsepower rating, measure the shaft diameter carefully. Also carefully measure the distance from the center of the shaft to the mounting surface. Compare those measurements with a NEMA dimension chart. The motor has a TEFC, totally enclosed fan cooled enclosure. It appears to have a "C" face. If there are threaded bolt holes on the face, that is a "C" face. You may find that there are two or more HP and RPM ratings assigned to the frame and shaft size of the motor. Getting the motor to run and determining the RPM will narrow that down. The most common RPM is near 1800, the other two common speeds are near 3600 and 1200 RPM. The full load speed will be about 2 to 4 percent below those speeds.