Old police cars were white and baby blue weren't they? Mine's more of a middling blue, but it's hard to explain colours on the internet isn't it!
I'm no expert on 1970s Minis but can tell you the rear lights on yours are of the later type (1976 onwards) as they have built in reverse lamps. However this means nothing as they are the same fitment as the older ones and could easily be swapped.
It looks like the wheels are 12" Minilite style ones which were available around the late 80s/90s but again easy to change according to taste. And there are weird screw on arches?! Not seen them before.
I don't think it would take a massive amount of effort to put that car back to original, if you wanted to (good on you if you do). Shame the roof rack wasn't included, I bet it's worth a fortune!











