Tom, I can’t see how that number can be possible. Simplex was running on fumes by 1957, and was only building about 1500 bikes that year and less each successive year.

Now, what I do see as possible is that being the original engine number, without the M prefix and B suffix.

Your frame number would lead us to believe that Simplex was still very active in production deep into 1960.  All of those units would have been a mixture of different models and not just scooters.

I am in Auburn near Bay City/Saginaw area.  Where are you at?

I found the original publication that published this article on eBay and bought it.  (Buzzzz Sept. 1954 No.9)

 What was written in the club magazine article certainly does not align itself with the original article.  Upon re-reading their article more inaccuracies become evident.  Plus, someone had written '1934' on the page but the bike resembles 1936 models.  This is one of the pictures I spoke of where the Delta Defender might have been used on '36 models.  The captions are quite different from one another.

The original caption mentions vice-president Powell being in the picture.  Soon I will be posting company letters signed by him.

I really like the green.  My name is Tom.  I seldom post on Facebook but that was me that asked about the frame number.

That's a nice set of......wheels!
Feb. 2, 1946