I just bought some 18c's exclusively for the battery door for my 28s's broken one.

[BruceH]

A new door is all very well but a decent proportion of the broken 28s that I've seen are broken in the body so the door has nothing to latch onto. For these there is no easy fix other than Katie Wasserman's half-length battery fix that takes the pressure off the door entirely. This also avoids the need for a 'donor' machine.