Frank Adam wrote:
anything that is smaller that the diameter of the hole
and can push that pin in will do.

Thanks. A pin seems strong and small enough. I can easily grind the
point off and put the watch in a maple-edged vise.

Imagine a tube with two pistons inside, being pushed apart
by a coil spring between them.
Kind of like a drum brake slave cylinder, if that helps

Hmmmm... I am very familiar with drum brake slave cylinders.
I didn't realize this, but, are you saying the "spring bar" actually
STAYS in the body of the watch? I *thought* this spring bar was to be
pushed all the way out (like when adjusting a watch band where the
"pin" is basically two arms of a very small half-round cotter pin
folded over to look like a single cylinder.

You'll have to push the pin on one end, while with your third hand
pulling the band (gently) away from the case.

There it is again! Am I to assume with one hand you push in one side of
the spring bar; with the other hand you push in the second side of the
spring bar; and with your third hand, you pull the Jubilee bracelet
away from the lugs on the Datejust watch body?

Would you kindly clarify that the spring bar holding the watch band on
STAYS on the watch body at all times?

This is fascinating!
Rusty