If you're gonna tidy it up, do it all or not at all. Else sell it back on and get something fresher.
+1
Sand the laminate down with a power sander, belt sander on low settings would be ideal. Then use a good quility primer undercoat, which you can really get some coats on, my scratchbuild had four coats onto sanded mdf, so you may require more.
(if you plan on doing a black or dark coloured cab, add a bit of that to your primer because it will make it easier to cover when you paint your top coats)
After you've primed, check over the cab for scratches or chips or marks (because the primer will show these up) then fill them up with your preffered filler (make sure you can paint straight onto it), then lightly sand the primer as a key for the paint to stick to, then clean any dust off with methalated spirits (make sure to only use a little) leave the meths to dry, then paint.
Solid,