Rather than an organization, it is an award or distinguishing badge within the Masonic group he belonged to. He may have been a member of the officials in charge or it could be a display of the length of his membership. Think of it as a 5yr, 10yr, etc, badge. Also, think of it as a different but same group altogether. Who and what the Masons are now, are not the same as back then. They may be the Masons, but those in charge back then are not in charge now. Some ideas and values change through time. Simply put, the province is the area covered by the influence of the local lodge, the old guard is the leadership in charge of the influence. The pin or badge says to newer members that he is a member who has been around for a long time.