From my website -
Shells can be swapped between the two versions, although the forward numberboard detail (with its arm of light-conducting plastic) is very different between the two versions, and as a consequence, a bit of a sticking point. Based on my experiments, the old numberboard part does not work with the new chassis (and vice versa). Consequently, I had to leave said numberboards with their original chasses when performing said shell swap. Also, the old shell has a raised section on the inside that tends to interfere with the lightboard on the new chassis. Sanding down said ridge definitely makes for a better fit.
-Mark