Well I took the paper backing off the frame......it feels and handles like a many years old dry tree leaf. It's amazing what a simple piece of paper hides behind it!
An extremely thin wood 'shingle' held in place with what appear to be hand made nails covered a page out of an art book of some sort. Henry Graves & Co. has quite the history in itself! Near as I could find they were still printing under that name in 1901, a few years later it apparently joined another company and published under both names. The back side, which only bears a page number, clearly shows the impression from the printing process.
On to the 'backing' of the photo itself, which I thought was likely similar to a card stock. It's a thinner piece of paper, similar to a book page that seems to have been tinted around the edges. (Handwritten notation on the 'art book' page states 1" Brown.....possibly instructions?) Interestingly, the side facing me bore a 'picture', likely a copy of a painting by another artist. From carefully moving the paper away from the edges of the photo (which itself is firmly affixed to the 'card' that bears the photo and the photographers embossing) I can't see anything printed on the back as is shown in the examples of their work in a previous link I posted. I think the paper is glued full surface with the exceptions of around the edges. There may be printed text beneath but no way to tell.
For a few minutes I thought I might have to change the old lady's name from Hannah to something more fitting of royalty but a quick read through gave me the date of Gainsborough's work. I think my lady is definitely more interesting than his duchess
