It is a 1hp two stroke engine fitted with a close coupled centrifugal pump, which appears to be factory original, and carries on the cowling the makers name details as follows:- O and R Engines Inc., 3340 Emery, Los Angeles, California, 90023.
"O and R" stands for 'Ohlssen and Rice', who made engines for model aircraft and I believe that it was manufactured in the 1960-1970s.The only numbers I found on it were stamped on the crankcase and are:- 13A235 (a type no. I suspect) and 1072316 (possibly a serial no.). As you can see, the cowling is red and the pump is yellow.
This 'mighty midget' only measures 6" x 9" including the pump and is only 8" high to the top of the spark plug!
It is mounted on a small aluminum base plate with rubber feet on each corner and I can easily grab it and pick it up with one hand!
To give you some idea of the size of the engine, you can see a Honda G300 piston sitting along side it on my bench. Even more amazing is th4e carburetor which is sitting on a Victa lawn mower wheel for comparison!