When fitting the rear dampers (and probably the front ones as well) there is a large gap between the damper and the mounting plate, what do i use to fill this?

washers unless you've got a lathe
same as the ones supplied with the bolts 2 either side
tony

How much play should i have between the damper and mounting bracket? Should it be a tight fit or should i be able to move the damper slightly? Does this change once i tighten up the bolts?

Snug is best, the damper usually has a rubber mounting anyway.