Main question is the state of the chassis, especially the rear axle mountings and whether they are still solidly attached to the chassis sidemembers. If these go it is very difficult to reattach them entirely straight. If the car has lived in Cleethorpes all its life this is a seaside (salt air) environment.
In this connection you should be aware that, if you are into restoration, it is possible to remove the body from the chassis, which makes welding much more straightforward.
If underfloor welding is needed this is no big deal. Likewise dodgy body panels as these should be available from third party suppliers.
Looking at the state of the front "A" panels it is possible that the front bulkhead may be in poor shape. But again, this is not a terminal problem.
845cc engines were available on late-plate French models, so should be OK for spares availability, but items of décor such as dashboard components could be more difficult. Also the doors are the obsolete "old" type with external top hinges. Rear suspension components can also be problematical as the pattern of swinging arm changed in later models. But again, there are specialist suppliers (Französe, Mélun) who may be able to help.
If the thing has only 50K miles on the clock the engine should be good for at least another 100 thousand as long as nobody tries to run it until they've refitted the radiator!!
R4s around "T" plate time were manufactured in Ireland and the build quality was notoriously poor so they need even more constant attention to rustproofing.
The vendor says "Webasto style sunroof" but from the pictures it looks suspiciously like an original Renault factory-fitted item as illustrated in the official Parts Book. If so this makes it excessively rare — I'd be surprised if there were more than a dozen RHD original-sunroof models left in the UK (including the one currently languishing in my garage waiting for a well-moneyed buyer). This has implications for collectors' value.
The vendor is right to say that RHD R4s are getting hard to find. If you are willing to spend a not insubstantial amount on restoration this car looks like a desirable item, although the price is possibly a bit high. Bear in mind that if the car were fully restored it would probably take more money to restore than would be reflected in its ultimate value. But we're not in it for the money, are we?
