101 Engine DGP18XX and Magneto/Dynamo Identification help

[Hollywood]

I bought this Indian Scout Motor years ago and am looking for any additional info on it or the Magneto / Dynamo that was on it. What I have found out so far is that the motor (according to the Oregon Trail chapter AMCA Indian Serial Number chart) is the following:
1928 Model GEP/101 Engine Number Range – DGP100-DGP4317, Horse Power 6.61
Description: 45” 101 Scout changeover year from sf Scout, mostly assumed 1929

Here's what I think I remember that I was told when I bought it:
The guy I got it from, I believe, told me it was used as a hillclimb or racing engine of some kind and told me the name of the guy's shop in NY (I think) that it came from. I just don't remember any of the facts...wonder why?

The Motor has 1/2 inch stroker plates under the cylinders and the Magneto/Dynamo is a Robert Bosch Germany. The pics show all the detail of markings on the mag.

Any Indian/Magneto experts out there? Help!