I have found this identical medallion in Bing images under the search thread "Liberty Tree Medallion." But, I have also seen the same medallion identified as a "Quatemoc coffee medallion or token".
I don't think the later is correct because all the other Quatemoc medallions/tokens are adds or premiums for Guatemalan coffee and are marked accordingly. I don't think it's older than perhaps one hundred years, but I still hold to the belief that it is a Liberty Tree Medallion. Most of the other repro medallions have "Sons Of Liberty" or "Liberty Tree" on them, but the Sons of Liberty was a secret society hotly pursued by the British authorities. I believe that if they had/wore a medallion it wouldn't have said anything on it. There has to be a Boston Historical Society that could give you more info or perhaps point you to a source. There is also an association of the descendants of the Son's of Liberty. You might contact them.
Best