Search Craigslist Seattle and enter 3939S in your search. The ad is for a HiPo Button Top fuel pump stamped 3939S with a late '66 date. The seller notes it has been restored by fuel pump guru Fred Ballard. Asking price is $1,850.
I do not know the seller and have no affiliation.
That's mine, been listed here for a while...https://www.saac.com/forum/index.php?topic=32865