Projects 1931 Production #S Question

I have a decent A frame out from under a '31 tudor…
found the production #s under the left cowl side...
6 digits followed by a star...
they made 5 million As so a '31 would be in the 4 millions... 7 digits..
memory says the #s start and end with the stamped star...
the frames #s start within 1.5" of the front body mount hole...
I wire brushed, painted white, then sanded with fine paper and a block...
don't see any stampings [* or #] out front ?
any ideas ?

 

Acid scrub should show the #.Ask the police how they do it.

 

Battery acid works and wash well after use.

 

I guess what am asking is did all fords #s start with a star ? …
did ford restart the #s every year with a designated digit to determine year ?
or are all As in the same run of numbers ? ...

 

Also not all frames got a number,the engine is the place for serial #'s.I think all started with a* (star)and finished with one also.Google Ford Garage,good info there.

 

I just used muriatic acid on mine today, Started with a star followed by 7 digits .