This is a parcel Post Obliteration
(common for a 1/- stamp)
made of rubber or cork, aniline inks often used
Double ring , with the name of the town running through the centre.
Your postmark is
FINSBURY PAVEMENT
Finsbury Pavement is a short length of street connecting Moorgate with City Road in the London Borough of Islington. It forms a part of the London Inner Ring Road (as the A501 road), and before the introduction of the ring of steel around the City of London it formed a major through-route towards London Bridge and south London.
Example (North Finchley) (Hipstamp)
