HI
He is not a Sitting Primo. If you look at both sides of the Collar you will see the letters W and P this is Worthy Primo (basically the same as Sitting Primo). Worth Primo / Sitting primo is basically the chairman of a Minor Lodge meeting and he holds the office for one month at a time.
The ribbon on the medal (known as a Jewel in the RAOB) will be blue. This medal is a second degree medal. The style of the medal is now a defunct style and is no longer in use. The 2nd degree is different now. However it is still blue in colour. The Cuffs and Apron are also 2nd degree. They would most probably have been presented to him when he was raised to 2nd degree. The chain collar would have belonged to the lodge adn was presented to the WP every month.
The style of this medal tells me that he was also member of the RAOB GLE (Grand Lodge of England) This is the largest of the RAOB banners
To be a Worthy Primo you will need to be at least a 2nd degree. Maybe this photo was taken as commorative photo to celebrate their first time in the chair
This is a link to the same jewel http://www.s119595638.websitehome.co.uk/gle__primo_2_130x280.jpg
RAOB GLE Plymouth is still active. There is a member now in my lodge who moved to Lincoln. Look at the website and contact the Provinicial Grand Primo, pass him the name of the person in the photo and any info you have. They will have access to every single Plymouth Lodge records in existance. They can tell you, date of initiation into the orderm which lodges they belonged to, attendances, degree dates etc etc. The GLE keeps some very detailed information on all members. If his lodge is still active its possible they are still using that collar today
Paul Richardson
RAOB GLE Lincoln