[ColdWar_Conan]

Hello,

As you most likely know, there are two types of cap badges around... Those which slide in, and those which poke in with a pin and backplate. I have a couple of questions regarding them.
Firstly, many of the pin ones are sold without a backplate. Is this how they were issued (and then worn - with just pin and badge)? Or has the plate been lost over time.
Secondly, what is the significance between the two types? Did they change from one to the other at a certain date, or are they issued as and when, for example.

Thanks
Conan