One of the advantages of the Nokey sewing frame is that it is easy to loosen, then retighten the supports to sew a book in the round. Sewing in the round is less invasive than flattening the original backing, then rebacking, and incidenally is quicker. However, thick books such as the one pictured take me a while to sew: I am no where near as quick as an experienced sewer in the mid-nineteenth century who could sew between two and three thousand signatures a day, according to “A Day at the Bookbinder’s” from The Penny Magazine Supplement Vol. XI, December 24, 1842, p. 380.
Three sizes of the Nokey are available here for purchase.