I've only searched 4 boxes of nickels, but I got 2 war nickels and a Buffalo. I usually get less than you in pre-1960s, about 25 per box, so you did well.
Like Mental Unrest, I'm starting to question why I am saving everything pre-1960. I may dial it back to pre-1956, or even pre-1951 (I've yet to see a 1950-D anywhere other than in a coin shop, but I'm still hoping to find one). There were simply too many made for them to have any premium whatsoever...UNLESS you sell them on Ebay. However, with all of the fees that they and Paypal charge, I'm not sure that its worth it any more, not unless you have a lot of rolls that you can sell for $4 or more each. Nonetheless, I don't have so many that I'm dumping them yet. Maybe when I go through a few dozen boxes.
Note that I am saving the 2009 nickels (I get almost all Ds), as that is the rarest regular issue since the mid-1950s. I didn't see one of them in change (still haven't) though I've gotten over 100 since I started getting boxes.