These signs are on the wall of a shop - the Pharmacy, as it happens - a few doors away from me.
They read 'C.P. 1877' and 'S.P. 1852'
I suspect that they are to mark the then boundaries of Clapham Parish and Streatham Parish respectively, although I have no specific proof of this. My supposition is based upon my - by no means expert - knowledge of the local area where I live.
But there could be an entirely different explanation!
