Help ID Antique Button - Colonial -

I have been unable to ID the age and use of this Button. As in simple Colonial area, Revolutionary War, Militia, Regiment. It is about 23mm. (.907", shy of an inch)but looks like it might have been flat or concave and now its convex from being crushed. I dug this up in North East Massachusetts. There is A Mid 1600"s Home with in A 1/4 mile from the button dig sight and an early 1700"s about 1-1/2 miles away and was part of the underground Railroad. Button is heavy and looks like pewter or similar make up to me. The Marking is raised and is slightly off set from center shank mark. I don"t know what the marking is. I have looked under listings like Slash, Stripe, V, L and also 7. Any help would be appreciated in dating craftsman style make up to help Id. time frame of my Button. Thank you