I've been corresponding with the seller. He got it from the estate of Charels Zembower, an Itasca crewmember. The scrapbook is interesting. Several of ther documents included definitely date from the Earhart cruise but there is only one photo that I can verify was actually taken during that cruise - and it's not the "smoke screen" photo. We've had a copy of that photo for many years. We got it from Itasca's quartermaster Frank Stewart. Frank was not aboard for the Earhart cruise. The photo shows Itasca "blowing tubes" (cleaning the boiler tubes) off Howland in 1936. Elgen Long has the same photo mislabeled in his book "Amelia Earhart - the Mystery Solved." The one photo I'm sure is from the 1937 cruise is on the same page and shows a group of Pacific Islanders lined up on the deck. We have a photo of the same scene from a different angle taken by Jim Carey, the Associated Press reporter aboard Itasca. The photo was taken during Itasca's search of the Gilbert Islands.
The seller doesn't know who put the scrapbook together but he assumes it was Zembower himself. That's probably a safe assumption. More to the point, the seller doesn't know when the scrapbook was assembled and captioned. If Zembower put it together later in his life that may account for the mislabeled "smoke screen" photo.
Bottom line: it's an interesting scrapbook but not a significant or particularly helpful find.