I think it took me a full week to spin each bobbin of singles -- very, very thin singles.
And then it took me another week to do the plying, a little here and there and then a marathon session of three hours Friday night and two hours Saturday morning.
In the end, I wound up with approximately 680 yards of laceweight two ply as well as a smaller skein (yardage not measured) of Navajo-plied leftover singles from one of the bobbins. The finished yarn is now hanging to dry after its bath, so I can't show you a fully finished picture. I love the results. The yarn is shiny and the color is muted, even compared to the original fiber. It will make a lovely shawl, eventually.
P.S. Happy Solstice and Happy Chanukah to those of you celebrating!