Here are the docs.....it doesn't really say they started with 101 but since both docs mention it as the first number I think it's safe to say that at least the production machines started with those serials....maybe there were pre-production ones, but I've never seen any.
Note that also the cocktail table serial numbering starts at 101 so I think that was the way they did it.
By the way, the German flyer is not the only place where your version appears, it's on the manual too, and in smaller size on the U.S. Flyer.