Wonderful Pic!
I can certainly explain the collars of office for you.
Your GGF was CW (City Waiter) for the month and as such would see that all members had refreshments available.
On his right is the City Secretary, responsible for the lodge's administration.
on his left is the Sitting Primo, who would have been in the chair of the lodge for the month.
next is the City Marshal, who would assist the SP in his duties.
then we have the City Tyler, would would allow entrance to latecomers after checking credentials.
Second left in the second row is the City Registrar, responsible for collecting regidtration fees and seeing that the members sign in.
next to him is the City Chamberlain, who would see that all members are properly attired and would act as a kind of Maitre'D within the lodge.
two along from him is the City Treasurer, who, as the name suggests, would be in charge of lodge finances.
Standing beside him is the City Minstrel, who would lead the lodge in singing the toast to absent brethren and the National Anthem.
the two officers in the back row are the City Constable, responsible for collecting ant fines imposed by the Sitting Primo, and the Alderman of Benevolence, responsible for recommending any payment to a brother in need. The AB would traditionally be the previous month's Sitting Primo.
Hope this helps, and if you have any other questions I'll do my best to answer them for you.
Kevin