By way of a little historic interest, I have a few primary notations of their use by military and militia. Does anyone have a primary mention of civilian use?
Cuthbertson, Bennett, Esq. A System for the Complete Interior Management and Oeconomy of a Battalion of Infantry, The Second Edition. London: J. Millan, 1779
"
On Service, leather Hammer-stalls are undoubtedly an advantage to a
Battalion, when loaded, and resting on their Arms, as accidents may be
prevented, by having them then fixed upon the hammers of the Firelocks; but
at other times then can certainly be of little use."
Orderly book of Col Meredith’s Command of Independent Militia Companies at Hampton near Williamsburg, on home guard:
July 11.th 1776
Parole Hampton
"That each Soldier make a Leather cover to the Steel of his gun which is to be kept on the same--
"
Great Britain, Royal Artillery Regiment Library, Woolwich, Brigade Orderly Book, James Pattison Papers.
"It is left to their [officers] discretion in time of real Action to disencumber such men as they may think proper entirely of them [arms], taking care that they be lodged in their Ammunition Carriages and to prevent any possible Accident happening therefrom, thumb stalls have been ordered to be provided which the men are constantly to keep on the hammer of their pieces except when posted centrys."
Captain James Stewart, 42nd Regiment, Feb. 1760:
“The men’s arms to be in perfect repair and to be completed in stoppers, pickers, brushes and hammer caps, which ought to be of black leather…”
Spence