Hi There Wehlmer:
Why not try this:
Take a piece of cardboard, smear the end of the PTO shaft with grease, then tap the cardboard into it with a rubber mallet, so you've got an impression of the end of the pto shaft on the cardboard.
Then do the same for the stub shaft on the mower.
Then mount the mower to the tractor and measure the distance between the end of the PTO shaft and the stub shaft on the mower , and mark this measurement on the cardboard.
Then head for the largest TSC or Farm and Fleet you've got in the area
The farm machinery/PTO shaft section.
and see if you can find something to fit your dimensions.
I'd start off looking at their collection of yokes first, cause the parts are small , to identify the size and type of couplings needed, also to measure how deep the pto shaft and mower shaft goes in the yoke. Each of these measurements must be added to the measurement you made to obtain the total length of the shaft.
Then when you've got that nailed look for a pto shaft that's got the end fittings you've identified, and is the right length or longer than what you need. You can always trim it to size later.
Just looking on the tsc/ff web sites I see shafts for between $160 and $200
now if only one of them fits.
On the other hand if the proper shaft includes a slip clutch , that will muddy the water.
Hari.K