Looks like a Gweduck or Grumman Widgeon. Post war, a few Widgeons were retrofitted with flat-six engines made by Continental (IO-480, 260 hp) or Lycoming (GO-480, 270 hp).
Gweduck is a project to develop a composite replacement for aging Widgeons. So far only the prototype Gweduck has flown.
SECAT 30 was a licensed copy of Grumman Widgeon built in France post-WW2. SECAT was built with metric hardware, but less corrosion-profiting than Grumman production.