Though never actually being released, a Beggars Guild stamp was scheduled in the first issue of the Stanley Howler Stamp Journal, and a image of it was included. Based on a pre-used 50p Cabbage Fields, the important details, including cancellations, are scrubbed out and a suitable Guild inscription is added by hand. The addressee is expected to pay the postage fees. It is not clear however whether this would be accepted by the AMPO, or whether  a postage due stamp would also be affixed. It was suggested that the Guild would use whatever was available, including old confectionary wrappers. It is probably wise to handle mail from a member of the Beggars Guild wearing rubber gloves (available from all good stockists of Sonkey products). 

This is a mock-up of the Journal picture