If it is so simple and a guaranteed money spinner why not have a crack at it yourself lol
Seriously though, what you are describing will not make any/sufficient money for a manufacturer otherwise someone would be doing it.
If this what I wanted I would get an HW customised, reblued, tuned and custom stocked to my liking/specification. To get it all done to a high standard would be well over a grand plus the cost of the base rifle.
Ignore the reblue, get a nice enough but not special custom stock from CS Sheffield and a stage 1 or 2 tune and you could be looking at £400-450 plus the base rifle.
And if it really must be British start with a Tommy or a longbow.
Rich.