Advice for other members: What I did was watch Craigslist, found an older, gear B7100 w/a working frt blade assy (KUFD110) in Arkansas (903 mile round trip). The B7100 was rough, faded, some non-working functions, but good motor. I removed the blade assy & sold the tractor (first picture).
Since a gear B7100 is 5" shorter than a HST the subframe must be lengthened. This is best done while both pieces are attached to the tractor.
Roger