From memory the KDX seat is thicker, wider and has a much more square section than the KLX. I have just had the 73 CCM seat rebuilt from scratch. My local upholsterer has a passion for bike seats. He hand carved and layered (using muslin) the new foam, hand made a new seat cover, complete with original CCM logo, assembled it to the original base and charged me £50 ! Bargain.....
I have also noticed that there is a difference in the shape of the KLX seat base between the long and short seat versions.
Has anyone managed to measure their air filter yet ....... ? Please.