Robert Blossom then
This was a veteran actor even at that time, Robert Blossom had begun acting all the way back in 1958, which means he knows his way around. He had more experience by far than anyone else on the set of Home Alone, and we feel like it made the younger actors feel more comfortable.
Sadly he passed away in 2011 at the age of 87. We are glad to hear that he managed to live a full life and leave no stone unturned. You may also check him out in earlier roles in the Great Gatsby and Close Encounters of the Third Kind. This man really was all over the place back in his day.