Martin Hall Teapot E.P.N.S.

I am currently trying to fing out some information about this Martin & Hall EPNS Teapot . (Circa 1857) Sheffield,
Electroplate
Marked M.H. & Co (In a Shield).

[url]https://docs.google.com/leaf?id=0B_dkoczdMGzzM2Y4NTQ3ZGQtZjEyZi00YmRlLWI0YjgtZTg4NDhjOWVhNjIz&hl=en_US[/url]

[url]https://docs.google.com/leaf?id=0B_dkoczdMGzzZDZjZWVhYjgtMTE1NC00MmI5LTkwYzgtOGMzOTU0NjM4ZWUy&hl=en_US[/url]

[url]https://docs.google.com/leaf?id=0B_dkoczdMGzzODJhNjMwOTktYjVjYi00YmUzLWExNWQtMWJiYTdiY2EwOTdl&hl=en_US[/url]

[url]https://docs.google.com/leaf?id=0B_dkoczdMGzzNTA0ZDIzMWUtNGVkMC00Nzg2LWFlMWItMjUwODMxMTJmMmUy&hl=en_US[/url]

The Knop is Damaged. (Top Half is missing)

Any Information would be gratefully received.
MH2.JPG