Alright, did a full write up here:
http://www.tractorbynet.com/forums/build-yourself/392375-pto-capstan-winch-scratch.html
flingwing1969 - I consider the Norwood Skid Winch video to be...how shall we say, less than impressive. Skidding over clear, leaf-covered ground, is as easy as it gets. The videos of Farmi winches are typically much more interesting, stuff like pulling three trees at once through nasty terrain.
Originally I set out to just build my own clone of the Norwood, it looks so simple, anybody could build that. But hours of shopping for hydraulic motors came out with nothing that made sense.
High speed, low-torque hydraulic motors are readily available, but useless in terms of pulling power.
Slow speed high-torque motors are also plentiful, but all require massive flow rates, like 15-20 GPM. On the hobby-end of the tractor market, nobody has tractors flowing that.
I have no idea what Norwood picked for their unit, but given the video, I suspect they had to make a compromise in the end, and the unit lacks pulling power. Pretty sure my PTO winch easily out pulls it.
PILOON - If I didn't have a dual-shaft gearbox, I would have done vertical mounted drum. Working out the mounting for this gearbox in a vertical configuration was hurting my head too much to attempt, so I just went with horizontal.