British Pattern 1864 cavalry trooper's sword

[Ostrosky]

I recently acquired a 1864 p cavalry trooper's sword in South Africa. The sword was made by Robert Mole & Sons, Birmingham, and bears a Crown,/B/21 on the forte and a Crown/BR/21 (Birmingham Repair) on the spine. It has sold out of service opposing broadheads and a Crown 3 on the tang.

 

I have only seen this one 1864p in South Africa. When watching one of Matt Easton's videos on 1853/64 swords, he mentions that he has had only 2 1864s but 30 or more 1853s and asks, "What happened to the the other '64s?" Some seem to have gone to the West Indies and Canada around the time of the American Civil War, but some were used in the Second Afghan War, though identifiable photographs or paintings are hard to come by.

 

I'm trying to establish which regiments were issued the 1864 p swords, and when, whether British units or those in the colonies, West Indies, Canada, or even South Africa. Any documentation, photos or detailed paintings will be appreciated.