If you are speaking of the silver communicator and not the wrist com the dimensions are as follows, width 2 3/8 inches, length 4 3/8 inches, and height 1 1/16 inches. Aluminum project boxes can still be found at http://www.mouser.com/search/Refine.aspx?Ne=1447464+254016&Ntt=*kab3421*&Msb=0&Mkw=+kab-3421&N=1323038 and are supposedly like the ones used in the film. The serial number is LMB # KAB-3421 for the die cast enclosure. Hope this helps.
- John
Upon looking further at the site I see now these enclosures are in black instead of non-finished aluminum. I’m sure this is a problem that can easily be taken care of with some fine grit wet/dry sand paper and a buffing wheel.
Is it possible the comms were rented from Modern Props? I read somewhere that the WOK tricorder and some of the set dressing were but I have always wondered about the communicators. -John