An 18ct gold single stone diamond ring

An 18ct gold single stone diamond ring, an old mine cut diamond, estimated as approximately 0.31ct, claw set to tapering grooved shoulders, and a plain shank, Birmingham, 3.11g.
Finger size Q (approximately)
Sold for £160

Condition report:
Diamond measures approximately 4.00 x 3.10mm.
Diamond slightly off set in collet.
Wear to claws.
Shank out of shape.
Surface marks/scratches to mount.
Some porosity to inside of shank.
Original hallmark nice and clear.
Some dirt to underneath of diamond, would benefit from being cleaned.