Well, now hear this. The USS Ling's museum has a Bofors and I have an M103 trailer. Before too long, both should be under restoration, then Haze Grey and Underway as a parade float. Any of the guys around here who read this are more than welcome to come 'n play. Veteran's Day will be a miracle; Sussex is a possibility. Memorial Day or Bust. It'll look best at > 10'.
To keep this on topic, I obviously can't comment on Vietnam, but I've been all over the Internet for photos and information to use in the restoration. The Bofors apparently started as an Army weapon, and there are a number of pictures of it on its actual trailers. I found the TMs for both the gun and the naval conversion necessary for salt water operations. I haven't seen one on an M series 6x6 researching either period trucks in the past couple of years or the gun more recently.
Steve