Grüetzi Willi,
There was a Ford magazine published for the Swiss market in the Model A years titled "Ich und mein Auto" (in German) and "Revue Ford" (in French). Here is the cover of one of the issues from 1931 with a Roadster in some kind of a race:
In that magazine there are several articles about racing Model A's in various places in Europe including in Switzerland, Portugal and Belgium. Note the Speedster pictured in this article:
......and some more Speedsters in this article:
I know that you were looking for information from the US, but perhaps this information on racing Model A's in Switzerland, Portugal and Belgium may be of interest anyway and might help convince the Swiss authorities about your Speedster.
With Model A greetings from Maryland, USA,
Brad