Telcolor was not based on C-22 but on the Agfacolor principle. It was spectrally universal sensitized. For neutral-density vs. colour-density gradation tweaking it got a silvermask.
As said that film has got a silvermask and needed a process taking care of this. This process was offered by Tellko and exclusive laboratories.
Nonwithstanding Tellko published this masking process.
However for less quality demanding users there was chemistry offered for a more simple process based on the Agfacolor-principle.
It seems Ian has got the latter formula here:
(there was a url link here which no longer exists)