Birmingham Fire Brigade was formed in 1887 & lasted until 1941 merging into The National Fire Service ( 1941 to 1947 ) during ww2 ( world war 2 1939 to 1945 )
Birmingham Fire Brigade was & still is the 2nd largest brigade in the country with London Fire Brigade being the largest operational town / city fire brigade from early years to present day.
Birmingham Fire Brigade had 3 different pattern helmet badges in use during its lifespan from 1887. This helmet badge used on both the brass & the leather fire helmets they wore is the 2nd pattern helmet badge worn from 1920 to 1927 when they changed the badge & button design. The helmet Birmingham Fire Brigade wore operationally was leather, the brass helmets were used for ceremony only !
This helmet badge is the original issue brass badge which has been chromed at a later stage in its life, but is not one of the official Birmingham Fire Brigade chromed badges that were officially chromed by Birmingham Fire & Ambulance Service in 1953 to mark Queen Elizabeth 2nd's Coronation. Around 150 brass helmets were chromed for the occassion & i am aware that West Midlands Fire Service still have around 130 of these & they have been engraved underneath the rear of each helmet WMFS. The badge that was on the official chromed helmets is the later pattern 1927 to 1941 badge, the leather helmets had bakelight grenade helmet badges for this period. 
The badge is original & you can see the original brass showing through the chrome which i have mentioned is totally unnofficial & not chromed by Birmingham Fire & Ambulance service in 1953. The central helmet bolt & both fixing lugs are intact to the rear of the badge which is a one piece cast helmet badge.