Alex;
Sounds an interesting idea! A "parts-tank" or shop special.
But, not to be all wet-blankie and such... probably, IF there was zimm on the sides, there would be zimm on the glacis and zimm on the rear plate, as well.
A "cannibalized" KT could donate a complete hull or a turret, or wheels or tracks or a gun or hatch-covers, etc., but probably not separate plates from that hull, and, so far as I know, all KT were made either with factory zimm (Sep 1943 to Sep 1944 production), or after the zimm order was cancelled (SEP 1944). Therefore, not likely, it seems, that one could get a Tiger II with zimm on only part of its hull.
It IS plausible, I think, for a zimm'd turret on a later-production non-zimm hull, and maybe vice-versa. And this leads of course to interesting "what-if" paint schemes such as new turrets in red-oxide primer on old camo'd hulls, etc.
But, of course, this is a model - and it's YOUR model, and it can come out any way you really like it!
Bob
Photos have survived showing Panthers, early and late TigerIs and IIs with Zimmerit on the hulls, but not on the turrets and vice-versa. That means some form of cannibalization is evident, as having been done by German Maintenance Crews- that is, if there was time. 
