Need some advice regarding a copyright issue

Tricky question here.  I bought a box of film negatives from the early 40's from a garage sale.  I had  some prints done of these shots and fast forward a couple months and have had a number of inquiries of people who want to buy some of these prints.  Do I own copyright of these photo?  The original photographer is unknown and assumed deceased.  

Can I sell these prints?

From reading this: www.copyright.gov/circs/circ15a.pdf

it sounds like those would fall under the 1909 act. Which means that they would be grandfathered in via the 1978 act. Which makes them under copyright for the life of the creator plus 70 years. So the question is, when did the photographer die? If that was before 1950, they're public domain now.

However: you bought the negatives. A case could be made that rights were transferred with those, but I'll bet that the sellers didn't think about that. And much like the work of Vivian Maier, you can own the film and not necessarily own the rights. Can you go back to where you bought them and get a signature? Unlikely, I'm sure. Unless there was some sort of agreement by the heirs, no, you don't own the copyright.

The work of Vivian Maier has this sort of problem. Read about it.

https://www.copyright.gov/circs/circ01.pdf

"How Long Does Copyright Last?

In general, for works created on or after January 1, 1978, the term of copyright is the life of the author plus seventy years after the author’s death. If the work is a joint work with multiple authors, the term lasts for seventy years after the last surviving author’s death. For works made for hire and anonymous or pseudonymous works, the duration of copyright is 95 years from publication or 120 years from creation, whichever is shorter.For works created before January 1, 1978, that were not published or registered as of that date, the term of copyright is generally the same as for works created on or after January 1, 1978. The law, however, provides that in no case would the term have expired before December 31, 2002, and if the work was published on or before that date, the term will not expire before December 31, 2047.For works created before January 1, 1978, that were published or registered before that date, the initial term of copyright was twenty-eight years from the date of publication with notice or from the date of registration. At the end of the initial term, the copyright could be renewed for another sixty-seven years for a total term of protection of up to ninety-five years. To extend copyright into the renewal term, two registrations had to be made before the original term expired: one for the original term and the other for the renewal term. This requirement was eliminated on June 26, 1992, and renewal term registration is now optional.For more information on the term of copyright protection, see Duration of Copyright (Circular 6) and Renewal of Copyright (Circular 6A)."