Hi, Isandlwana,
Try as I might I cannot make out what the collar dogs are, your sight must be better than mine.
However, I hate to be pedantic but, the Elephant superscribed Assaye was granted in 1803.
The cipher F and Coronet of HRH The Duke of York and Albany (1763-1827) was granted in 1823.
The Duke of Albany that you refer to (1853-1884) was Leopold who was Colonel of the Regiment,
his Cipher L with a coronet was borne on the cap badge worn by officers and warrant officers, this was adopted at the request of Queen Victoria.
Regards
Bob.