The Mystery engine  is a Villiers 4-44

Made in England, circa 1965

                                   The muffler on the restored engine is not what the original would have looked like. 

                                    It is a four stroke side valve engine and rated at 4.5 HP 

                                    The tappets are adjusted by shim and bucket mounted on the cam followers.

                                    The original colour is green, similar to Brunswick Green.

                                    It uses a crank handle for starting.

                                   It has a Villiers BV 1320 model carburettor

                                    The barrel and fins are cast iron, the head and crankcase alloy.

                                    It is fitted with a wipac impulse magneto number: CJ1671 5 62

                                    The only other thing I can find is what could be an engine number stamped 

                                   into the crankcase: 23076-10

I have been looking information on this engine for a number of years without being able to find anything really.  Thanks to Des for his email telling me what it was.  I was able, leading from his information, to look a bit deeper into it.  From the U.K. Stationary Engine Forum I learnt it is a 'cross-breed' between Villiers and J.A.P. and this occured after the Villiers and J.A.P. merger in 1964. Its primary use was for factory trucks and such like.