Interesting about cushion choice. I had Artemis installed on mine because that seemed like the "in thing" at the time and right after that everyone switched to Superspeeds and said that was the best cushion. I swear it happened when my rails were in transit from Ohio back to Wisconsin.
Yeah I studied old threads on this topic and noticed the same. The Artemis rock! Well worth the extra money in my opinion.Interesting about cushion choice. I had Artemis installed on mine because that seemed like the "in thing" at the time and right after that everyone switched to Superspeeds and said that was the best cushion. I swear it happened when my rails were in transit from Ohio back to Wisconsin.
Doesn’t Jeremy Chambers make new tops?
Yes he does. He does great work!
About 5 years ago it was approximately $1000.00 more for a custom set of Anniversary rails vs. having the originals overhauled. I would think GC rails would be fairly close in price.
4.75" may be a hair tight for the sides. I'd consider 4.875".
That may be what they are now... tightest side pockets in town are at Nicks
and I'm not even exaggerating 
The small side pockets may keep you honest when it comes to making balls but it gives you a false sense of confidence avoiding the scratch, especially when you go to a more common size pocket.
4.125" at 141° are going to be brutal with lots of rattles. With a tight pocket, you don't want the same angle as a 4.5" pocket. I'd reconsider 139° or 140°. My 4.125" corners were cut to 139° and I'd classify them as tight but fair. A ball struck well along the rail will not rattle but a ball with any pace that brushes the cushion on the way in will hang up; at pocket speed it will drop. IMO, this is how the pocket should play. I think at 141° the aforementioned shots will rattle.
Good question. I can only speak to 4.125" as that is the pocket size on my table. Perhaps a mechanic can chime in.