Cuprinol treatment of the ash frame was standard from 1986 IIRC. It was optional for a few years before - our first Morgan was from 1985 and the original build sheet showed that Cuprinol had been applied at extra cost.
I don’t know when it became standard to remove the wings before painting the car. Again, our 1985 car had wing beading fitted - which was optional and ensured that the wings were removed for painting. Any car without wing beading, of any vintage, could have been painted with the wings on - which leads to corrosion issues.
Currrent traditional cars (4/4, +4, Roadster) are all the same width inside whereas earlier cars varied in width which may be a factor for you to consider.
As others have written above, buy on condition. Look at several cars and the right one will choose you.
Welcome to TM and good luck with your quest.
