First, I am so sorry for your loss. From what I could find, George was described as a very kind man who, as quoted, wouldn't hurt a fly.
I've been able to find quite a few articles about the murder, the most important of which I'll link. His body was found on the morning of December 20, 1993, in the front room of his apartment, feet from the front door, which had been partly locked.
He had been beaten and stabbed, though I couldn't find any note of a part of his skull being missing. He was last seen at 2:30 a.m. on December 19, leaving the Unicorn Lounge, which from research, I believe is a gay bar. He is theorized to have picked up someone there. His car would be found days after his murder at a small shopping center.
Clipping found in The Indianapolis News published in Indianapolis, Indiana on 12/25/1993. Slain man's car is found
www.newspapers.com
Clipping found in The Indianapolis News published in Indianapolis, Indiana on 5/23/1994. Information sought in slaying
www.newspapers.com
Clipping found in The Indianapolis Star published in Indianapolis, Indiana on 12/21/1993. Lawrence man found dead; car missing
www.newspapers.com
Clipping found in The Indianapolis Star published in Indianapolis, Indiana on 12/22/1993. Man slain in Lawrence was beaten and stabbed
www.newspapers.com
Oddly, from what I could find, I found no evidence that George had been strangled in any way, but it's very possibly police didn't disclose this, nor the missing skull piece.
I haven't researched this case extensively, but George's movements shortly before his murder seem very close to Baumeister's known victims. I do recommend contacting to person also mentioned, to see if the missing skull piece may be among the bones found at Fox Hollow Farm.