Sorry, I changed usernames (used to be Hank.).
No one posted here about the converter box so I chose a different path. I am in the processing of bobbing my M35A2 so I will be using the wiring harness off my M105A2 trailer for a set of detachable lights with magnet bases. This will allow me to haul civilian trailers and not worry about converting the harness. You can pick up a M105 trailer for $150 + fees. That gets me the bobber bed, secondary air system for my split brake system, wiring harness for detachable light project and a few dollars in my pocket for scrap.