What appears to be an officers silver and gilt badge is in fact a badge produced by the Birmingham Mint in the 1970’s.
These badges were made by JR Gaunt (the company who owned Birmingham Mint purchased JR Gaunt in 1973) and were made as part of a commemorative set celebrating infantry regiments. These could be classed as copies rather than fakes.
The features that identify these badges as Birmingham Mint copies are the slider (Officers badges were not made with sliders) and the metal which is shiny and new looking.
It should be noted that as these were commemorative badges, they were never issued to soldiers.