broke a u-joint on 54d MMM mower, help sourcing a replacement?

I have a 54d MMM mower (1023e) with the PTO shaft that must be engaged manually. I managed to break the joint on the mower gearbox and need to source a new yoke and cross/bearing assembly. Can anyone supply any part numbers or (even better) non JD sources? Everything I am finding out there is much bigger then what I need.

thanks