Balmoral (Atholl) bonnet / black chequered dicing / 1960 British War Department

[The Wizard of BC]

OK, maybe I did not understand the original question.

I thought we were being asked to help identify a Balmoral bonnet.

I thought that we had been given enough information to identify that this bonnet could have been a British military issue item.

The only question then would have been is "What unit could have worn a bonnet like this and when?"

Am I being totally dense here? I don't seem to be able to make the connection to what color dicing some police forces use.

So, can someone help me understand. Was the original question by the OP - "Which police force wore this bonnet?"