Actually, I think my Hunter might the "B" model. I seem to recall looking for the original "A" model and only finding the "B", so I went with it. I think there were two iterations of the instructions, with the earlier one being the "A" model. Also, if you install the fan switch, it is not necessary to try soldering to the "G" pin, just connect the wire to the corresponding screw terminal on the mounting plate and you'll accomplish the same thing once the thermostat is mounted.
The link photo is not my install, but a photo I copied. The "ModMyRV" link are the instructions to follow for the "B" model.