I put the LX next to the K2. The LX is just as wide, but not as tall. The difference in height, however, appears to be entirely in the area covered by the top chrome cover of the K2. This means that the chassis and such of the LX could well be K-sized. The LX is noticeably rounder than the K2 which has the same body shape as the Spotmatics, so externally I doubt it uses much K series tooling.
Potentially the increased amount of electronics in the LX allowed it to be based on a K series frame and yet be shorter because circuits take up less room than gears. If the LX was conceived in the K era and took a while to develop then the fact that it isn't M sized makes sense. It's smaller than an F3 even so, and weighs a lot less, despite being a slightly more capable camera. DJE
