Hmmmm...good catch there, Steve. You'd think somebody researching this period set piece would know better than this, wouldn't ya?! And I've also seen a number of anachronisms in other movies over the years, and especially when it comes to the motorcycles and cars being shown in them.
(BTW...your synopsis of this movie reminds me of a similar sounding storyline in the movie "Summer Of '42", where you can view the "correct 1971 model" of Jennifer O'Neill...

O'YEAH..THAT was a good year for O'Neills alright!!

And even this 2008 model still "ain't too bad" EITHER, ya know...
