Can't tell you much about this, other than it is a field medical (surgical) tools sterilizer. Can also be used to heat sausages!
There may be a stamp outside the box or on the burner tank but very often they were completely plain to help cleaning. It has most likely been a part of an emergency field surgery kit for a military force - several countries used burners in that style and the rest of it is a design used worldwide.
I think it is a field sterilizer for medical or dental instruments. The larger pan is supported over the burners, and the tray with the holes is lowered into the hot / boiling water with the instruments to sterilize them. The wire ring / hook tools are used to lower the tray into the hot water to keep from burning your fingers. Paul
