1st Bengal European Light Cavalry
This was one of the new Regiments created in 1858 in the aftermath of the Mutiny with European (ie British) troopers, rather than Indian ones. The officers were drawn from those surviving from the old 1st Bengal Light Cavalry (which had mutinied at Mhow) and the 3rd (which had been the first cavalry regiment to mutiny at Meerut in May 1857) The Regiment was reconstituted as the 19th Hussars in the Queen's (ie British) Army in 1861.
A first-hand account of the creation and merger of the Regiment is to be found in The Diary of an Indian Cavalry Officer, Pagoda Tree Press, Bath, 2003. The diarist was John Hatfield Brooks, who was an officer in the regiemnt. The book also contains at plate 14 a photograph of Captain Brooks in the Regiment's uniform. I suspect this may well be the only picture we have of the Regiment's uniform.