Surely you mean '1:500': '50-inch' is 1:1250!!
I'd also be interested in tracvking down a copy!
From: A forum for issues related to map & spatial data librarianship on behalf of DGC-IP GEOLIB C1
Sent: Thu 2/14/2008 3:19 PM
To: [log in to unmask]
Subject: OS 50inch plan of royal dockyard Sheerness 1864
Does anyone know where a copy of the subject plan might be held please?
BL has OS 50inch mapping of Sheerness but the detail of the dockyard has not been included. Greenwich Maritime Museum has been very helpful in identifying other material but not the specific OS plan, and TNA does not believe that it holds a copy.
Hd of Geospatial Library, DGC