It is always hard to know what to do, put him down preemptively or just let him pass away from a long life, as long as he's not suffering.
He's had a good run, that silly cat. I will miss him so.
Here he is with a moustache. He was trying to get seconds on the wet cat food, pretending to be another house cat. I think he told me his name was Ventley Srdlik. Clever fellow.