Acvoke
With thanks to John A for the first pic.
With thanks to Steve for these pics:
With thanks to Brian for this pic.
Patent information
With thanks to Peter for this scan of research by Dennis Commins.
Acvoke (brown grips)
With thanks to John G.
He says:
The gun looks to be in excellent condition, has had little use, and appears to have had no restoration work.
So what is it? My best guess is that it is an early prototype. This would be consistent with the known existence of two prototype bodies, with no serial number, that were found accompanied by a .22 barrel, a barrel with a cork-firing adapter, and sets of black and brown grips. It is believed that these were demonstrators used by J.B.Arrowsmith (the designer) in the early days of the pistol.
If Accles & Shelvoke were initially considering both black and brown grip plates, I wonder why they opted for black? To my eyes, the brown plates are classier and suit the pistol much better.