I remember reading somewhere about George Putnam and AE making the arrangements for the hops around the world. If my brain recalls correctly, it mentioned GP ensured she had customs clearance to fly over the borders and ensured enough fuel was at each stop. He would have paid by wire transfer for fuel and landing costs - I need to find the article, maybe in AE's book?
AE probably had a bit of money for petty expenses along the way. If she did, it makes sense for her to have paper bills since they are much lighter then coins. There would be little reason for her to take money off the plane under the Niku hypothesis ... unless she was looking for something that would burn to start a fire with. Paper money would work great for that (of course FN had books, maps etc). There would be no logical reason to take coins off of the plane. I would also say TIGHAR has only searched part of the 7-site - from the photos I've seen there is a lot more ground to search.
It's all speculation, a lot of ifs and maybes which are about as useful as money stranded on a tiny island in the Pacific ... but still interesting. Time to go reading through TIGHAR's Earhart Archives and see how GP arranged for fuel to be paid at each stop.
Nathan.