Low mileage is usually because of a fair weather drive to the pub on a Sunday mentality. Having said that, higher mileages are rare for all sorts of reasons.
Just find a Morgan which ticks your boxes. Colour & trim, wires or alloys, spare wheel or not, easy up hood or studded.
These are the defining categories. But read the options list as well because some are quite basic spec and some have bells & whistles.
My Roadster is 18 years old. I bought it at three years old. It's been incredible.
My Plus 4, I had from new in 2016. The same. Neither have been back to a dealer. OK, I get dirty hands but that was the point.