This was in one of the Reveres with a MH ballast. It wasn't lighting, so I bumped the bulb and it started to light, then the lead wire sprung away drawing a bright pink arc. I immediately shut it off, this is what's left.
From what you describe, it may not be a bad ballast. It is possible that when the wire broke, the resulting arc ionized the outer fill gas and caused the meltdown. Unlike the tungsten electrodes in the arctube, which can glow white hot in MH at thousands of degrees, the outer metal supports would melt quickly with sustained arc under normal ballast current.
Lamp dates to July 1995??? Okay that's probably why it's dead!