I replaced the accelerator sockets with the metal variety, Peter. Most all mine were cracked anyway. The sockets are cheap from Rusty; I'm out of town right now and don't have access to the p/n's but Tom knew them anyway. They're all r/h thread btw & don't forget to order the locknuts if you go this route. There's one linkage that isn't adjustable, the vertically situated one; the sockets just spin on annular grooves on that one, so if you want to go metal with that one you'll need to hunt up an appropriate length properly threaded rod.
-joe