TURIN:
" Dropping a 'Curiosity' type rover on the moon would have been hugely expensive and considering the latitude and rocky terrain, not a particularly good idea."
Costly yes, but wheeled vehicles (both manned and unmanned) have trundled around OK in the Moon...but I agree not at high latitude and yes they are expensive.
Uplinker:
"I also wonder why designers don't use the same vehicle designs that have worked successfully before, e.g. the Mars landers"
Lost of differences between Moon and Mars though.. simply from a landing POV a Mars lander vehicle has to survive an atmospheric entry, which is not the case for the Moon, hence Mars landers usually have heat shields and parachutes in addition to rockets for the final stages...Moon landers rely entirely on rocket power.
There's lots of other really significant differences, for example day length ..or more importantly night length (that means different specs for the ability to survive low temps)..
Fundamentally switching a Mars design to a Moon lander would almost certainly mean significant redesign...whether you're talking about a stationary vehicle or a Rover.