This stainless steel locking diff actuator bracket works for both rear and front locking differentials in the VW T3 Syncro.  It is equipped with mounting provisions that make it compatible with...

Locking differential indicator switch. Not an original part but is a suitable alternative. Factory plug will need to be cut, and individual wire connectors will need to be used (included). Washer...

This differential lock actuator fork is what moves the locker from engaged to disengaged in your Syncro Vanagon.  Rebuilding your locker?  Consider replacing this fork.