olds starter changeover question?????

For what it's worth, several years ago I parted out a 1950 Hudson with a 303 Olds in it, and it had a starter changeover. When I ran the I.D number on the starter, it was listed as a stock 1950 Oldsmobile unit. Nothing appeared to be modified on it.

 

This makes a lot of sense. Why would the aftermarket guys spend the time and effort to make something that used to be modified, or needed a non-stock part? I have everything on the shelf. I think I'm going to mock it up and see what's up.