A shoe - but from what century?

Washed up on the surface of the south Thames foreshore was the first piece of leather I’ve seen. It took my 15 year old son, still woozy with sleep, to tell me it was a shoe, I’d thought it was some kind of purse. It then became obvious it was the sole of a shoe. The sole is made from two pieces of leather , with another piece attached to form the heel. One metal stud remains on the heel, presumably to reduce wear. The leather was kept together by small pins of wood pushed through handmade holes which surround the edges, at least 4 remain.

Shoe sole found on south Thames Foreshore, showing metal stud  and wooden pins 

Side view of leather shoe sole

I’ve failed to find any similar images on the web and have no idea how old the shoe is. I know enough to keep the leather damp, as otherwise it dries and splits. Whilst it was a delight to find, I really don’t fancy keeping something which needs care and attention, so I’m hoping the Museum of London might be interested enough to keep it. If they don’t, do I chuck it back into the Thames?