I've gone back into my French Indochina phase over the last few weeks after I picked up some lovely M29C Weasels from Butler's 3D Models. The French ran these armed with .30 cals, 57mm recoilless rifles and even 60mm mortars on them. I've armed three with .30 cals and one with the 57mm. They were able to traverse much of the soggy or flooded terrain, and were often supported by LVT 4s for more heavy support and infantry transport. These four models are based on those of the 1er Escadron/1er Regiment Etranger De Cavalerie, a Foreign Legion Amphibious Unit. The French referred to these vehicles as "Crabs" (no comments about how "I got crabs in French Indochina" please!), and the LVT 4s as "Alligators". All in all, a very simple conversion.