Vic Venters had a "Guncraft" article regarding the Hunter One-Trigger in the March/April 2010 Shooting Sportsman, which was (by permission) reproduced in the Journal of the LCSCA in 2020
https://books.google.com/books?id=rX8YAwAAQBAJ&pg=PT42&lpg

Lard's 1901 patent
https://patents.google.com/patent/US747191

July 21, 1901 Sporting Life 1901 GAH at Targets report
Mr. A.E. Lard was introducing the Westley Richards single trigger guns. It had detachable locks and was a fine piece of gun mechanism.




Shooting and Fishing, October 20, 1904, p. 30
The advent of the Hunter one-trigger action into the world of practical inventions marks a new era in gun construction. For the past three years the Hunter Arms Co., of Fulton, N. Y., makers of the famous and deservedly popular L. C. Smith shotgun, has not only been using, but it has also been abusing its one-trigger device, submitting the mechanism to the severest tests under conditions that were certain to develop any possibly undiscovered defects, conditions sufficiently extreme and purposely imposed to prove beyond the shadow of a doubt that the new gun could never be made to double or balk.
The following illustration shows the simplicity-of the Hunter one-trigger mechanism. It will be noticed that the parts are few and strong, a necessity in- these days of excessive loads of nitro powder. It will also be noticed that the entire mechanism while strong is wonderfully simple. The action of the device is positive and not dependent on friction in any way, which is an essential feature of great importance, as the locks of all guns, no matter how carefully they may be looked after, are apt to get more or less dirty and gummy, and it was discovered by the Hunter Arms Co., very early in its experimenting, that any one-trigger lock dependent upon friction would both balk and double.
After a long series of exhaustive tests the company, therefore, determined that nothing short of a purely mechanical device would produce positive and absolutely certain results every time the trigger was pressed.
The Hunter Brothers have always been extremely conservative in either adding to or taking away from the mechanism of the L. C. Smith gun, and this policy has been strictly adhered to in adapting the Hunter one-trigger for use in this gun, and the device can therefore be applied to all L. C. Smith guns, no matter whether of the older or newer types, as its introduction requires no change in the mechanism of the locks adopted by this company as a standard many years ago, and which, owing to their simplicity of construction, durability, and general excellence, have since become famous the world over.
A handsome new catalogue has recently been issued in which the Hunter one-trigger is shown to advantage, and in which its mechanism is described in detail.


1910 Norvell-Shapleigh catalog