John,
By the way, do these engines have only sandcast cases, or are sandcast engine ? As you know, sandcast engines has some different parts than diecast engines have. Hard to believe Honda had assambly complete sandcast engine among diecast engines. Can anyone asnwer this last question ?Yes, and what are these different parts of which you want speak? I shall like to know them to answer you because you move forward always of hypotheses without ever any real precision.
Give I lists her parts which you consider different enter Sandcast E-1007414 and Diecast E-1007415? Or even E-1007515? Or another E-1007615? E-1007716?
If you dismantle them, you will notice that they are identical 99,99 %..
The assembly line of engines Diecast was exactly the same (at the beginning) that for engines Sandcast, the internal parts were the same and the alone crankcases engine and cluth cover were modified and not only on some hundreds..
I do not even imagine the high authority Honda to say has his workers: We pass has the production of engines Diecast then you throw the old stocks of engines Sandcast!!
Here are photos of the various parts of E-1017118 and who can say without making a mistake that they would not have been able to result from E-1007414? Or a lower number? Certainly nobody..
And you did not more answer has Steve very very good question:
John, how do you KNOW the frame/engine combinations are not original ?If you have an original list Honda of the numbers VIN-E he would be interesting for the group to know her..
G.G