An interesting punch: it is usually believed that the "GR crown" punch was used for King George IV (1820-30) and then in the XX ° for King George V.
However, these razors are typically dated between 1760 and 1780 for the shape of the blades (dip-at-toe) and characteristics of the handles (turtle and typical silver tips) in the range of luxury products. So, GR is also for George III.
The "LONDON" punch is used by Samuel Linley (son of William Linley cutler. Freedom granted in 1772) and by John Linley (son of William Linley cutler. Freedom granted in 1770) (Gales & Martin 1787 directory)
Attachment 291191
Attachment 291193
Attachment 291195