drain coolant, no need to drain oil I think, take the waterpump off and put back together with silicone gasket maker
I would replace the elbow o-rings just to be on the safe side
get the parts blasted for best results
degrease with panel wipe
always use acid etch primer on alloys and preheat even to 200deg centigrade prior to coating (cool down first of course)
if it starts cold without choke then you have an overly rich mixture which will stall the engine when hot, but mainly only at idle. if not carbs then plenty electrical points that can go wrong when hot (wires changing resistance when hot) and you need to check. i would start with main wires first...
high chrome or extreme chrome as some call it, tried it on my wheels some time ago, clearcoat is a must otherwise it will go dull in no time...
rubbing is not really an issue on wheels, but it's so much easier to keep clean than chrome...