I would respectfully seek advice or guidance on a point of interest

I have in my collection a number of R.W. Palissy trinket boxes from the fruit range the Palissy base has numbers for example 8-1, 12-1 ect (Attached is typical)

I would be interested to know the significance of these numbers and how to interpret the meaning, I believe they may be some sort of date code.

I would appreciate your assistance in this matter or your guidance as to where I may obtain the information.

Thanking you all for your anticipated information in this matter.