Cory, the salesman is scum, or at least a know-nothing.
See if he has the manual to the car, prove him wrong!

There should be a pullout knob below the center of the dash, kind
of infront of the gearshift, plus ome sort of display with a green light
above it, usually with a schematic of the chassis. Pull out, move
vehcicle a few feet, green light goes on, diff is locked.

I thought diff lock was standard on all US Syncros as late as '89,
(what say you, Jim Davis), but that could be wrong. Was this vehicle
imported for the US market? 

Post the FS info on the 3,000 mile Westie, its of general interest,
IMHO.

Good luck, 

Tom F.