Iain,
If you park in the car park near the harbour and come out of the exit near the Gima supermarket, cross the main road and go up the side street opposite which has a restauuarant on the corner just up here are dozens of little hardware shops, we always use the one farthest on the left hand side, we bought a variable speed drill with hammer action for £12 last year. In fact you can have a play with it in April if you like !
The shops here are just like Aladins cave, they have everything.
Rimms