Hoffnung & Liebert Seal, Image & Found by Barry Norris.
Found on Essex/Hertfordshire border.
Dia. = 20mm, Thickness = 4mm Weight = 9g
Markings as shown on diagram. GRAUDE is probably the start of Graudenz, the German name for a town that has swapped from German / Prussian to Polish nationality several times. It is currently Polish, Grudziądz. The town is famous for its beautiful old granaries that suggest this could be a flour bag seal.
See also the Konigsberger Seal which has a similar RO/I inscription on it.
From Paul Cannon, "I can confirm that this does relate to the city of Graudenz, currently in Poland but at the time of the seal under German control (West Prussia). The following links to an image of the mills in 1910 Albert Gieseler, Mannheim, Germany 2009. This source records that it was milling rye and wheat. Several German directories are available on line for Graudenz eg the following is dated 1901 Adress-Buch der Stadt Graudenz und Feste Courbiere : Nach amtlichen Mitteilungen zusammengestellt, 1901 page 111 indicates that 18 Getreidemarkt was occupied by Hans Hoffnung Getreidehandler (grain dealer) who was Mitinhaber (co-owner) of the Graudenzer Mühlenwerke Hoffnung & Liebert Dampfmühle ie the Hoffnung and Liebert Graudenz mill works steam mill.
Based on this and what I can see on the seal I believe it is possible to reconstruct the full inscription as:
GRAUDENZER MÜHLENWERKE (9 o’clock to 3 o’clock)
HOFFNUNG & LIEBERT (across the centre)
*GRAUDENZ * (7 o’clock to 4 o’clock)"
From Philippe Lanez, "'R 0/1' farine de seigle = rye flour" Also see Euro-Plombs for other examples.