Could you help identify this cap?

[M1dg3]

Hello,

thanks for stopping by.

I have recently been given this cap and I’m wanting to restore it by adding the necessary buttons, cap badge and chin strap but I have no idea what regiment if any it is. The inside tag is missing but I do have this label suggesting a CPL D Flanagan and a 234 SQDN which I read as 234 squadron. I don’t  know any information about a Flanagan but have found 234 squadron relating to the RAF I’m just not sure why it would have a white rim if it was an RAF cap though as I’ve got a few other caps and from I’ve saw they never have that. Could it be an RAF police hat or something. I have no idea any help identifying this cap would be greatly appreciated. Thank you very much. (It looks black in the photos but it’s more of a dark Navy blue)

[Preppy Picker]

It’s British but that’s as far as I go.