My sources show several men named Young as gun makers, but the most likely seems to be Joseph Young of Harpers Run, WV, listed as a maker of full stock percussion rifles. No dates are given, but there is a T. Davidson & Co. listed as a lockmaker in Cincinnati, OH, 1850-1854, which seems about right for your rifle.
If you care to remove the barrel from the stock (very carefully, please) you might find the name of a barrel maker on the bottom. By that time, there were few "whole gun" makers; almost all bought barrels, locks, furniture and semi-inletted stocks and were essentially custom assemblers, like custom gunsmiths today.
There is a rifle with the Davidson name shown here:
but it seems to be of a different style.