Interesting article.
I have met the last man to play with Chet - Dutch pianist Rob Van Bavel, who was a regular at sessions at my friend Malcolm Frazer's house.
It is said that on his last day Chet stopped by the club where Rob's trio was playing, sat in for a few numbers, went to meet his connection and returned to his hotel - from which he never re-emerged.
Here's Rob at Malcolm's: