I went ahead and cut the winch cable, and took it to the local rigging shop to have replaced. Hopefully it will help with the sticking. I also bought some very liquidy graphite solution, and a silicone spray.
Regarding it being stuck, before cutting the line I disconnected it from the keel and did two things:
1) winched the cable up without the board
2) Lifted the board with a jack (without the cable)
This quickly told me that the cable was jamming, not the board, when its completely raised. Some poor photographs of it raised below show that it is related to reaching the end of the wire, and getting to the thicker swaged connection, or the tangs below. You can see the swaged connection hitting the wheel below...
So my only hope is that a new cable and trying to lubricate the wheel help, otherwise I guess I'll just keep a tube available to hammer it down.
At least until next year...