This is a really difficult question to answer as it’s such a personal choice and significantly affected by your body shape/size. I bought my current Morgan from a guy who was 6ft 4in and had a tiny wood rim wheel fitted so he could get in and out. At 5ft 9in I couldn’t see the instruments clearly and have fitted an offset flat 14 inch wooden Moto Lita wheel with the thicker grip for more comfort. Being offset it supposedly provides more leg room and makes it easier to get in and out but can’t say I really notice any difference.
I had a thinner rim Moto Lita on my first car that looked great but I found uncomfortable and the most comfortable was a leather Moto Lita 14 inch leather rim. Personally I find 15 inch to be too big but others like them.
I can only suggest that you also need to consider whether you can actually see the instruments clearly as well as the rim size/thickness/material. Then there is the option of a quick release wheel which I like the sound of but have no experience.
Good luck. The great think about a traditional Morgan is that you have an almost unlimited choice of wheel, the bad thing is that you have an almost unlimited choice of wheels…
