Reply and point him here. He certainly does not believe in giving out information, does he?
The Hopkins & Allen can reasonably be dated to c.1880-1915 or so. Would need some more information on the configuration of the gun to be of any more use there.
Winchester made a bunch of .22 short rifles in different models, but at least he gives us a patent year. That would be correct for the Winchester Single Shot Rifle (Model 1885). The patent date marked on that model is October 7th, 1879. If that is correct, the gun was made very late in production and may very well be a Winder musket c.1918-1920.
If your correspondent could provide information as to specifics and condition I might be able to help further.
The autonomic nervous system provides for involuntary muscle function - the work of breathing, digestion, and so forth. On some folks, that's a pure waste of ingenuity.