Neat find! It is a livery button design. I think the backmark might be FIRMIN STRAND LONDON ? But you would be able to see it better to confirm. That company has been around since 1677.
It took me a bit to figure out what those things are! And I'm still not sure but I think it may be bear paws and be a match to the family crest of the Harvey family.
Wow,i knew it was a old one and yes there has always been Harveys in the area since this area was settled in the late 1600's. you just never know whats going to come out of the ground here. I would date it from the 1700's. thanks for the id.