The M4P is inherently a very rugged camera, steel gears, brass top and bottom. If, as the seller states, the rangefinder is clean and aligned and the shutter curtains are OK - it might not be a bad camera at 150-200 pounds - and factor in a check of shutter speeds and curtain conditions. If it is still working - it will probably continue to do so. The winder, if it is the M4-2 winder is worth next to nothing, the key is that you get the regular baseplate with it. As for the looks - it is not a thing of beauty - but it is surprisingly dent free. Almost looks like someone has tried to de-chrome it with steel wool!
In the days of film - the big cruise lines operating out of Vancouver equipped their "grip and grin" shooters with M4P's - some of these cameras had 3-400 000 actuations in a couple of years. Usually required new curtains and sometimes a tightening of the film advance - thats it!
I would pick it up - have everything checked out (speeds and curtains) and if the look is too offensive - tape over the finder windows and give it a quick coat with black Hammer tone paint.
I would not bother with a full CLA on it - just enough to make it work and that should cost maybe 40-50 pounds.