It is hallmarked but does not bear the standard mark which leads me to believe it may be a foreign piece. The hallmarks present are, from left to right, '925' 'anchor' (on its side) and the 'a' for 1900. Below that there appears to be an 'up-side-down' makers mark - a Capital C followed by a small O.
Any information or advice would be appreciated.
Thank-you.