History of the Ithaca single triggers
https://doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=617152

Researcher posted a long list of single trigger patents for which I'm looking.

BTW: "Blue Rock" was unimpressed wink
Guns, Ammunition, and Tackle
Albert William Money, Horace Kephart, W. E. Carlin, Abraham Lincoln Artmann Himmelwright, John Harrington Keene 1904
http://books.google.com/books?id=G5ECAAAAYAAJ
As to the single trigger action on a gun, which is being pushed very hard at the present time, theoretically it ought to be a vast improvement on the old-time action, and at one time I was persuaded that it was only necessary for a man to get used to handling one of these guns to beat anything he had ever done before. I remained unconvinced that I was wrong for nearly two years, despite repeated failures, and spent much money on this new fad; but, like every good shot I know who has tried them, I went back to the old two triggers, and I am fully assured that even if the action were quite perfect, and as little liable to fail as the two triggers, that there is no real benefit to be gained, but rather the reverse.