Thats okay too. If he wants to restore it, he should get in touch with other Dutch, Belgian and other local European members of the KFOCI (the fellow from Germany who is coming to Belgium for example), or simply join KFOCI. With membership, there is access to the Manufacturing Fund which has reproduced some hard to find parts, especially plastic knobs and rubber window gaskets, and floor mats I believe. Other club vendors can supply most other parts--even some unused chrome pieces are still to be found. Since the engine is a Continental, internal parts should be easy--The British company Massey Ferguson tractors used Continental engines, at least in their North American versions.
If it was a 4 door convertible, or a special 4 door hardtop, it might be much more of a challenge, but a 4 door sedan is a fairly simple proposition. Kaiser purchased many of its parts from suppliers, like Borg-Warner transmissions, and so forth, rather than making all their own parts, so there are a lot of parts still available as they fit in many different applications, from tractors, to portable compressors, to forklift trucks and so on. When I went to do a complete rebuild my 49 engine with new valves, pistons and other parts, the shop in the village 11 km away had almost every single part needed on the shelf, and the few bits they didn't have, they had the next morning from a warehouse in a nearby city.
Good luck to your friend.