Google "parker wheel motor parts " Download the pdf from Parker about torqmotors, should be the first pdf ya come to. Also check out J Thomas site, they have some cross references.
Have Googled for a cross reference? Fleabay has a bunch of em listed.
The original parker seal kits run about $58 or so, not sure about the bootleg kits
The bearing can be had from any bearing supply.
Now the shaft.............