Thanks, I have a spare in a parts box somewhere from when I left my keys sitting on the bbq grill on my balcony for 4 days. I was walking out the door to AutoStore to borrow a steering wheel puller when I thought, "one last check....."
Couldn't recall if the external chrome collar was integral to the lock cylinder or a separate part.
EDIT: I need to do the "loose GM steering column teardown/rebuild", that others on this site have kindly, generously, and extensively documented, anyway. So I will go get that steering wheel spring plate compression tool thing for real this time.
I know others have made their own, but alas I live in Hollywood and street-park (barely.) I wish I was a clever redneck McGyver with 14 acres of peace and auto parts. I see y'all's "garages" and I ... "covet" is the best word....
BR