Just looked on Craigslist, there is a local guy selling a junker 1650 for parts. No motor, no wheels, though they show it as a roller in the photos. Was thinking of picking it up for the ported hydro pump and the lift cylinder to upgrade the setup on the 129. Are the parts similar enough to make it a bolt-in upgrade, or will I need to make major modifications to make it work? I don't really have much direct experience with the QL series tractors, I know the engines use a different starter and are set up differently, use isolation mounts etc.
I half expect to have to split the tractor, it might be just as easy to swap the whole hydro pump/transaxle assembly into the 129, or make the 1650 into a 1250, depending on the condition of the pieces.