That diff that got everyone confused is from TRC. Don't know if they actually produced them themselves, but thats from where I got mine. That was before they joined Trinity. If one look more closely at their 12scales they sold at that time, they look VERY much like the Delta ones. Difference being that the plastic was black instead of "Delta red". 10 year old stuff. Doubt one could find spares. Perhaps the diff was originally made by Delta? Anyone know?