Was Phantasm Ravager planned 30+ years ago?

In the absence of news or a release date for the new Phantasm sequel, phans have taken to examining the previous four films for clues as to the direction of David Hartman's fifth. And - surprisingly - one of those phans has come upon irrefutable evidence that Don Coscarelli had secret plans for a fifth Phantasm when he first made the original film back in 1977.

Have a look at the video below, which was submitted by the talented Filemon Pi Piripi, and be sure to pay close attention to Reggie's truck!