I acquired a Holland&Holland 1910-1912 catalog from an antique dealer a few weeks ago. One ad was for this scope with elevation turret. I guess the marked elevation turret is nothing new. The ring in front of the eyepiece is for focusing. I could not find any reference to power of the scope. It sold for 12 Guineas. I just thought you might find it interesting.

Very interesting! The gentle taper of the ocular housing looks surprisingly modern for that time. I imagine it was about 2.5x.

I suppose it might have been made by Ross in Britain but the distance marks on the turret suggest Kahles to me, as they apparently made scopes with ranging provisions as early as 1904. After WWII H&H seemed to favour Zeiss and the newer Nickel Supra scopes.