I'm afraid i haven't found out too much more since yesterday and don't have the ability to get too many more photos just yet. Gary - what did you mean about 'lineal descendants' above?

If the gun is marked for the early 1930's then this is at the beginning of the careers of l G Thomas and possible engravers! And i can't find out too much more re engravers - the Meek book is available on Amazon from the States but we think there is nothing in there?

thanks all