S Series Geroler Motor, 13.70 cu in/rev, 4 Bolt Mounting Flange, 1 in. Straight Keyed Shaft, 1/2 NPT Ports, Compact yet powerful|Extended bearing life|Increased shaft seal

Mounting-wise, the 4 bolt flange and 1 inch straight keyed shaft line up with what you're describing, so the mechanical fit should work out. Ports are 1/2 NPT, and the displacement comes in at 13.70 cubic inches per revolution. As long as your system is running premium anti-wear hydraulic fluid and you can keep fluid viscosity around 70 SUS at operating temperature, you're in good shape to run this motor in a harvester application. One thing worth doing before you put it under full load is running it for about an hour at roughly 30% of rated pressure to break it in right.