Mystery solved! Phil Bunce was THAT GRAVESTONE

"I distinctly remember that evening (at least the early part of it) because not only did I build the gravestone I also allowed a space at the front for turf. And guess where that came from? Methuen's front lawn!!! I also remember arriving at the entrance which went down to the cellar and was barrel vaulted. The gravestone, being rectangular, and me being pissed anyway were definitely incompatible. I tripped, wedged myself and the gravestone in the entrance causing a fire hazard and stopping other party goers from gaining entry - I don't think it was a popular choice of costume but you did remember it at least." Phil  '76-79