I have a Great Britain Perfin with an overprint that may be common to people that collect UK, but the perfin and the overprint stumped me?


I found out that the stamp was issued by the provisional government of Ireland in 1922 Rialtas Sealach na nEireann.

Looks like this page has been silent for a few years, so I am hoping there are still people with ready answers.
If yes then I have a few more to identify.

Also is there a reference to identify British Perfins, since I have 86 I want to list and would like to know if any are valuable?

I am curious when scanning the back of stamps that have perfins is there a desired color to put under the stamp. My scanner has a white background, should I add a black or other color to make the perfins stand out better?

Thanks in advance!

Vic the stick!