Post Box (again)

Following on from my blip of Dec 12th, and a suggestion from my sister, whilst out for our stroll today in the conservation area of town, I found this postbox bearing the initials of George V (1910-1936).
The maker’s cast-iron base shows it was made after 1916 when they moved to Falkirk, and before 1930 when they ceased working.
I wonder where I can find an earlier one now!