I have been thinking long and hard about this one. It's not that i'm slow (perhaps a bit stupid) but it needs a lot of thought as to why and what the replacement needs to offer when a Coupe or Aero is the baseline.
It comes down to the experience more than the detail. It is a total alternative to a good working eurobox at so many levels. Noise, speed, looks, other travellers reactions to it. It also happens to drive like my consideration of a sports car, quick, responsive and fun.
I get caught between two routes. Fast/wicked (Nissan GTR35, 997 Turbo) and classic (Pagoda Mercedes, Lotus, Classic 911, Early Aston) however the prices of these are not to be underestimated, as well as operating costs. However each of these only scratch half the itch and so don't quite make it.
I guess the Morgan really does straddle the boundaries unlike many other cars. As others often say a real usable classic.
If forced to pick something that would replace it as an experience I might go here
http://www.marceatoncars.com/used-cars/bentley-arnage-6-8-t-4dr-southport-201505183562794 Not this specific model or company but similar. It does have the same integrity as the Mog and a very different but equally deep experience.