Use a hairdryer to soften the glue. Dribble either white spirit or Wd40 down the back. Floss works but will leave some residue which will come off with either of the above.
MSCC sell flag badges. If you buy from e bay quality varies. Some have imitation screws.
There are two sizes, and I prefer the larger size. I think mine came from Heart of England....I'll check.
Just looked, but I can't get the image to zoom. The ones I use come with dummy screws which I don't like, so cut off and polish the edges...……...
