It is indeed a [British] United East India Company musket. The "V" in the symbol is a Romanized "U" as was the fashion at the time, to copy Roman stuff. The "4" is actually a ship's mast with a sail, ... well it's supposed to be....
View attachment 166375
The lock mortise is too good for it to be a replacement lock. The 53rd as a previous post gave information, had a battalion posted in India by 1805. Now the date on the lock is NOT the date the musket was made. It's the date the lock itself was made, and very well could've been on that musket in 1796, but more likely it was stored until it could be made into a musket, likely post 1800, as the engraving shows only one unit marking, and if it was made prior to the arrival of the 53rd, it likely would show the previous unit AND markings for the 53rd.
The engraving on the top of the butt plate is correct for the time and place, as the thumb escutcheon was omitted from this model Bess. The question would be then, did the 53rd Regiment of Foote obtain UEIC muskets after getting to India as replacements, or did they completely arm the battalion with them?
OH and I'm not sure, but it looks like the ramrod is wood? Can't tell if it's metal missing a tip or wood missing a tip, but all India pattern and later British made 3rd Model Bess had metal rammers.
LD