This is an original R.D.F. busby badge. It is not to be confused with similar badges on the market that are clearly reproduction.
I can confirm that this is a genuine busby badge for several reasons. I acquired it recently from a collector friend of mine who has had this as a swap item for many years. Take a look at the lugs on the reverse. They are quite long, over two cms. in length. The reproduction badges have much shorter lugs. This badge is also lighter in weight than the reproductions. This badge is die struck in brass and as such has very clear and crisp definitions. The copies lack the sharpness of the originals.
So, buy this item with confidence. It is guaranteed original and well over 100 years old.