Following the pointer on un-notched leaf sights, I thought I should look in W. W. Greener's
The Gun and its Development (London: Cassell & Co., 1896). Greener does not discuss un-notched leaf sights, but
he does depict them, as part of what he calls a "cape sight", which also incorporates a folding slide that permits shots to be taken "at any range up to 1,000 yards" (p.632).
[img]
https://www.dropbox.com/scl/fi/6oqe...qv0bpe1zofl76id&st=4pn45bi4&dl=0[/img]
Further references to un-notched sights can be found in the following classic publications:
1) Caswell, John, Sporting rifles and rifle shooting (New York; London: D. Appleton and Company, 1920), pp.56-57 (
https://archive.org/details/sportingriflesri00casw/page/56/)
2) Sharp, Henry, Modern sporting gunnery (London: Simpkin, Marshall, Hamilton, Kent & co., 1906), pp.257-59 (
https://archive.org/details/modern-sporting-gunnery-1906/page/260/)
