Disston never carried an open-handled backsaw in its catalog, with the exception of the "Jackson" brand backsaw in the late 19th century and the "Davis" in the early 20th century. Jackson was a second-line brand with lesser quality in materials and finish than the Disston brand saws. It is shown with an open handle in the 1890 catalog. Later the Jackson saw was made with a closed handle only. Davis was of similar quality and featured an open handle in the 10 and 12 inch lengths.http://www.disstonianinstitute.com/openhandle.html

If we discount Disston's #68 & #70 Dovetail Saws, and the example listed above; its a little puzzling as to why Disston restricted their range of backsaws to closed handles only under their own brand. Provided the handle wood Disston were using was well seasoned; and the forward weight of the saw blade assembly is restricted within reason, weakness within its design makes little sense if you take into account the range of open handle backsaws being offered from u.k saw makers pre 1900.

I am currently working on some 12 inch open handle tenon saws; fitted with 0.020 saw plate; and thought it an interesting topic of discussion.

Stewie;