That is a seriously nice rifle

IMHO the early hammer doubles are most interesting, straight stock with finger rest, non rebounding locks with "stalking" safeties all point to an early rifle
The brass blocks and very unusual hammers are a bonus
Clear Damascus figuring and the foliate engraving all point to a top class rifle

Wilkinsons apparently did not produce many DRs (I only have a Howdah pistol by them)
Only one of my DRs has the fold flat sights a .450/400
Is it 2 3/4" or 3" case? (or even 3 1/4")?
A very good catch indeed
Hope you have fun shooting it

TH