Roughly mid to late 1910's on age. Great find on the shuttles, as far as I know these were NOT sold by Boye in their needle and shuttle containers. Sort of surprising considering every Davis 3/4 size machine uses this shuttle. Later Davis hand cranks have an arm that goes into a groove in the hand wheel pulley. My Model T has no pulley as it can only be friction driven by motor. If it did have a pulley on the handwheel, it would have to be cut to fit the Crank arm. Here's a link to better show the later Davis Crank set up:
http://treadlestitches.blogspot.com/...sters-for.html
http://www.ebay.com/itm/ANTIQUE-DAVI...item1e7fc1d854
Jon