G&G mec box shell in a TM?
 

Will a G&G m4 mec box shell work to fix a cracked TM one?

Will the Internals all transfer over? Do I need any parts Side from some shims?

Should be fine.

the internals will transfer over fine.

G&g shells for a good many years have not had the upper receiver tab holes in the back of it. So if your tm has upper receiver tabs, not work.

A little delayed but the only difference was the need for larger bushings :)