4 seater are like hen's teeth. They are so practical that owners are reluctent to sell.
I would always buy a Morgan from a Dealer, to ensure you are getting dealer's cover.
We have owned our 4 seater for 15+ years. Like Ruut, we bought when our son was young. It worked well the three of us for trips aways such as Classic Le Mans.
It is a 1989 model, and is a 4/4 with a Ford CVH engine. The parts are plentful, although becoming rarer to find. example
https://www.carandclassic.com/car/C1584409As with the car owned by Ruut, the rear seat sits higher than front seats, which is fine for children. I do carry four 6ft males on short journeys from our campsite to Le Mans, but this is only practical for short distances.
The car is ideal for camping trips (if you need extra space you easily remove the rear seats), supermarket shopping, or to carry suitcases etc.
the most recent 4-seaters were as Plus4 or Roadster models. These are larger, with proper rear seats (those made before 1999 where beach seats), example
https://www.carandclassic.com/car/C1607177
