Re leather seats - our first Morgan was a 1985 4/4 fitted with vinyl upholstery and trim from new. When we viewed the car, decided to buy it and started negotiating it quickly became apparent that the dealer concerned was reluctant to reduce the price at all. However, he was prepared to increase the specification of the car. So we got leather seats, a walnut dashboard and a few other bits and bobs included in the price.
My point is - if you view a car that is not quite the specification you want, it may prove substantially cheaper to ask the dealer to do things as part of the deal using their trade buying power than to take the car as is (even at a discount) and then get the work done yourself.
Good luck.