Mreed,
I have had the intent to respond for the past couple of days, however I have been extremely busy. I hope the following at least gives you a jumping off point.....
The Forker family of gunsmiths has a brief write up in Henry J. Kauffman's "The Pennsylvania-Kentucky Rifle."
Attempting to avoid plagiarism I will summarize his research...…
John and Samuel Forker ,were the sons of Adam Forker whom was listed as a blacksmith by trade. It is apparent that two of his sons (John and Samuel) became gunsmiths. There is a possibility that Adam also had a son by the name of Joseph born in 1829 who was also listed as a gunsmith, however only worked in the trade for 8 or 9 years. Additionally, there is a possibility that another gunsmith by the name of Israel Forker was a gunsmith in Ravenna, Ohio in 1837, and was possibly the son of John Forker. The above is just a summary, and I encourage you to seek the exact article from it's source.
The above having been said...please see the below photos for the Samuel Forker half stock rifle that I own. Quite the piece for a half stock of the 1850's era. The wood is exquisite. Due to my limited knowledge, I can't state much for your rifle, only that the stamp on the barrel looks similar to the stamp on my rifle....I hope this helps. I am sure others with more knowledge will chime in. Take care, and let's see some more photos of your rifle.