When a survey was produced of Plymouth Extension in the 1980's, I made a complete sheet of including all known surveys of all the the Bakers/Reeds area, with surface mapping also. This was given to the Pengelly who never returned it! I think the idea was to publish this, but when the Pengelly approached John Hooper (who was probably responsible for 50% of the survey at least) he apparently wouldn't allow his stuff to be used.
I think there was a considerable gap between GDS & PE, with no obvious leads for any sort of connection.
It would need a few caps or major bone reconstruction for me to get into PE nowadays, so perhaps it's best to leave it those who can (obviously a topic for discussion). Heard rumours that the DSS members who have been carrying on from where we left off with the Plymouth Extension survey have been getting close to completion, but only rumours.