from your description, my first assumption is that it's a print, or more specifically, a lithograph. If you would like to post a picture of it and pictures of anything you believe to be relevant, it could be easier to say.
anything in the condition you described should be rematted or reframed by a professional to avoid any potentially permanent damage.
if you are looking for its value, I always suggest seeing an appraiser.
a link to some information on Louis Brenton:
Louis Breton - Artist, Art - Louis Breton
a lot of links come up on Camilla Lucas. You can see a bit of what I mean for yourself:
Camilla Lucas artist - Cerca con Google