Milward serial numbers / dates

[Gravity]

I own two fly rods made by Milward, both staggered ferrule designs, and greatly enjoy using them. Each has a serial number inscribed on the butt section. I wonder is any member here knows how to "crack the code" to use these serial numbers to date the rods?

I estimate that both of my rods were made in the late 1950s or very early '60s but that is no more than guesswork. In my opinion, Milward is an under-appreciated maker, and one that deserves to be better known outside the UK.

Any help regarding the serial numbers would be much appreciated.

Stephen