There are reputed to be only 12 rare original gilt Merthyr Tydfil Fire Brigade post war 1948 to 1974 cap badges in existence. I am aware of a small handful in fellow collectors possessions, one is on the wall within Firefighter Mick Millards cap badge display at Hove Fire Station in East Sussex. 
This fake Merthyr Tydfil Fire Brigade gilt officers cap badge has been very well faked & would fool most avid collectors. So i have included extra pictures of a genuine original in my personal collection & this well made fake badge. 
Explaining the differences i can tell you several things about how & why the badge is fake. Firstly the person making it took great trouble to make it look as original as possible & several other badges i've examined from that same collection were made by the same person who bought cheap reproduction badges of rarer town brigades, then took the centres of which had long strap fittings to the rear, filing them down & drilling a fine hole, placing a thin brass pin through & attaching it to a more modern economy lined standard Home Office star. The giveaway's are the faint impression of the Marples & Beasley logo, a product of melting down faulty or non useable varied Home Office stars to make newer batches. The longer lugs precisely spot welded, a modern technique, older lugs from 1940's & 50's were shorter & chrome coated, well worn examples show the brass underneath ! These lugs are no longer available & have not been for many years, modern lugs are all chrome. 
I have tried to show the fake badge together with an original so my customers & friends are aware of these badges that are around. The original badge is on the left & fake badge on the right giving varied angles. The pin securing the centre to the modern star is also incorrect in that although a pin from an original badge, it clearly has been crudely bent & not standard factory fitting !