Old pocket watch identification. Help!

[Big_Dog]

I am looking to identify and maybe value this pocket watch. It has 18K and DM as the only markings I can find.
Really hope someone can help me out.

It looks to be enamelled on the back and is some 32mm wide. Says 1891 if that helps.

[Big_Dog]

Thank you, I have been through the actions that are near on there and the centre section seems to be the opposite direction. Interesting stuff though.