The hostler refers to a "fore boot" in addition to the rear boot, places for storing luggage,etc., belonging to passengers on the coach.
Can anyone tell me the etymology "boot" in this usage?

Two possibilities: the coach/car/whatever is thought of as metaphorically a person with the front being the head (hence bonnet or hood as the case may be) and the back being the foot (hence boot).

Boots were kept there.

Bingley

Dear Bingley: I wondered if "boot" were related to French "bout" but could not find any confirmation.

Or even more likely "boÎte" = box

I just discovered that WindowsXP has "charmap" available.