FWIW, you can do this yourself easily enough at very low cost. No soldering required, just use the existing cable, but modify with the appropriate connectors. Splice a UA5 plug onto the passthrough cable, and the MT's USB connector to the 5v cable (sorry, don't know the pinout, though I bet it's on here somewhere, or someone who knows it), using screw-on wire connectors. They're inexpensive, easy to use, secure, and field-serviceable.