I have been looking as well... I might try and get a set CNC locally. with 4mm hinge pins. I can get the material for 2 arms for about $10. My dad is a postman and has CnC Shops on his route willing to do work next to nothing for him...
If anyone has an old busted up set of Rpm True Tracks. Maybe with wrenched hinge holes or something. let me know I really want to get a set made. And if they come out good. I can maybe get a few sets made for the help... Thanks