They are all minis
FFrom 1959 there is very little that has changed about this great car.
- The older and rarer models are more valuable
- You have your early round noses with sliding windows and 3-syncro gearboxes
- Then they moved on to things such as heaters, wind-up windows and 4-syncro boxes etc
Then in the early 70's they decided to change the shape to the clubman (square nose, slab front, better looking of the two) model.
- They are generally cheaper as they are less desired due to not being the 'original' shape
- Really the ONLY difference for you is the shape from the windscreen forward, almost everything else went unchanged.
- Other differences include guages moved in front of the driver, lift up door handles, square tailights..
- The later you get, the more rust prone they are generally (up to 1978 Oz Cars) earlier cars fared better due to rustproofing.
The 1988 Mayfair you talk about is a Rover and all were round noses - some are fuel inj, though a 1988 would be carb, you might get 8.4" disk brakes and any disk brakes on a mini will add around $1500 to the price, but you'll need to run 12" wheels or above which some say ruins the original handling of the 10" cars.
Rovers are also have Internal Hinged doors and square lights like the clubman and they have rubber mounted sub frames which gives a comfortable ride and less noise, but feels noticeably different to other mini's so it's worth driving as many as you can to get a feel for what you're after.
Early '850' Round Nose with Sliding Windows:
Cooper S
Rover:
Left to Right: Clubman, Aussie Deluxe, Japanese Rover 1.3i
Original Clubman Interior
Original 76 Clubman S
Clubman Van
More..
UK Austin '850' - Sliding Windows
Roundie Interior
Yea...that's about it i think..