I've managed to get it working via a very convoluted route. Here's how:
- I have OpenSSH running on my home machine (a Vista box) running under Cygwin
- I am using Bitvise Tunnelier's Dynamic tunneling via integrated SOCKS/HTTP CONNECT proxy.
- I then use Freecap (thanks Marko) to "SOCKify" GIT-GUI. Unfortunately, you have to setup each .exe individually and run them from within Freecap, so you can't univerally SOCKify all of the git command line tools. You can setup explicit command-line commands within Freecap, but you have to setup each individually, which kind of defeats the purpose. This is why I've just setup GIT-GUI in this crazy elaborate system
Amazingly, it seems to work, although I've not tested everything yet. It'll clone, certainly, which is a start.
If anyone has a better solution, I'm all ears.