78-09-05 serial number range

[YankeeClipper]

I saw a thread here from long long ago, that briefly delved into the topic of the apparent pardon that the FAA seems to give to NA models after 33701852. I could find no more on that. What little was said, suggested it might have been a mistake on the part of the feds, given that 1853 was built--they argued--the very same way.

Can anyone illuminate me (us)?