This site has an interesting write up on the Australian use of the Collins AN/TRC-75 HF radio in Vietnam, including the teething problems they faced, an then later disposal and use of the radios by Ham enthusiasts.
http://qrz.com/db/VK2BLC#t_logbookOf interest to us is the detailed installation and use in 2A FFR vehicles, and the fact the owner moves his gear around in an ex-Army Haflinger trailer.
The pics below are from that site and sourced as quoted from other sources.