Older fleams tend to bear the initials of the the reigning monarch, GR for George III or IV, WR for William IV, or VR for Queen Victoria. Early in my fleam collecting career I bought a fleam stamped with a crown over GPR. This stumped me for a while until I clicked that GPR was Georgius Princeps Regens/George Prince Regent.
The Act (*) which appointed Prince George to act as Regent in place of his incapacitated father, George III, stipulated that the Prince should use the initials GPR rather than GR (being regent rather than king). This neatly dates the fleam to the Regency period which ran from 1811-1820.
This fleam has three blades, also stamped LONG LONDON, probably H. G. Long & Co., a Sheffield company which also had an office at 217 High Holborn, London.
(*) An Act to provide for the Administration of the Royal Authority, and for the Care of His Majesty’s Royal Person, during the Continuance of His Majesty’s Illness; and for the Resumption of the Exercise of the Royal Authority by His Majesty.
Source: bought online