I am curious what exactly gives you this idea? The members of SAMCRO are required to attend church (when Jax said he was going Nomad he said he would attend church wherever he was). Plus in every church scene it is always all the same guys attending. So who else is a member of the Redwood Originals that doesn't attend church?
Those who do not attend Church are usually out on a mandatory ride. You have to attend Church if you are not on a ride, not in the hospital or not in jail. Also, it's probably just from extras walking around in cuts that say Redwood Original and the pictures of other members on the Wall Of Mug Shots.
This came up in the Chibs thread and it makes me wonder how many member of SAMCRO there really are. I mean other than the main guys (Clay, Jax, Bobby, Tig, Opie, Piney, Juice and Chibs) is there really anyone else outside Big Otto and anyone else in prison. The fact that it is always the same guys in the church meetings makes me think no, otherwise there would be more a revolving door of members. As far as the guys on the mugshot walls goes, I imagine that is probably every member (or at least every arrested member) since 1967. I mean there are still 5 of the First 9 who are unaccounted for, so those guys are either retired or dead, but I am sure there pictures are still on the wall.