wear of white metal parts
I haven't noticed any wear, mine don't get run a lot. the main thing is you have to be very careful handling, as the side frames of the trucks can get bent very easily, throwing off the line shaft gear alignment. I had real concern about the white metal universals, but have had no problems, largely because they are just for the ride. on one side of the slip joint, I have replaced the square cross sectioned inside piece of the slip joint with a brass rod, so the rest of the line shaft is powered only by the opposite trucks line shaft gears so the lineshafts don't fight themselfs.
The actual driveline is all down the center, and has held up well. DR Tom's C&S #1 gets a lot of use, and has had lots of maintenece issues (similar to MDC Shays with a similar powertrain) bit no catastrophic parts failures.
another modification I have made is where the truck mounts to the frame. the little ball on the truck frame that pops into the socket on the frame. These balls are supposed to be heat staked to the truck (melted on) as no glue on the planet will stick to that enginering plastic. On mine those little balls kept coming off.
NWSL was good about getting me the parts, but the truck had to be completely disassembled to replace that ball. I used one of those KD plastic screws, chucked it into a drill to make a home style late, and truned the head of the screw till it matched the shape of the ball. I then tapped the hole in the top of this truck frame, screwed the new ball in place. Problem corrected!
Bill Nelson