Thanks everyone.
Knowing the name makes searching soooo much easier<g>
So here is what I have found out:-
I think that it is indeed a Mite 0.099 (1.62cc) Diesel designed by one Howard Mandeville, and first introduced by Walt Schroeder's kit company, Eagle Mfg. Co. of Brooklyn around 1947.
I have found a lot more information on line and some pictures of the complete engine:-
Interestingly the Alan Ortof review calls the valve under the crankcase a "throttle Valve" where other reviews think that it is a drain valve for a flooded engine.



There was also a glow version:-

