I don't know much about your tractor, but if a K48 MMM will fit your tractor I have one I may part with. It is driven by the engine crankshaft to a electric clutch. If your motor spins in the opposite direction of a b7100, you can uncross the drive belt to achieve the proper blade spin direction. The Orange Wizzards can tell you if this mower would work on your tractor.
I'm located in the Northern Berkshires, a good 3 hrs from you.