Out at lunch, here in East Texas. See an open carry in bib front overalls. It's a medium to large frame semi-auto in a nylon thumb break holster clipped in the pocket or the side button location, most definitely at "low ready position", laughably canted out, swinging, etc.

This got me to thinking about what would be the ideal method for concealed or open carry in bib front overalls, shoulder holster? What would work best?

I had my seamstress sew jean belt loops onto mine that take a 1.5 inch belt. Looks odd. Works great!
Other suggestion:
Sew a velcro panel onto the inside of the bib and use a velcro holster to carry the gun.
But it would have to be a lightweight gun!

Belly band would work.

Bib overalls would seem to be perfect for a snub nose revolver, subcompact or micro pistol in a pocket holster.

Depends upon what you wish to carry and whether it'd be worth your time to customize the overalls.

Stock overalls? A small, single-stack 380 or 9mm in a pocket for concealed or something bigger in a shoulder rig.

Customized? I've never worn bib overalls, so I'm just guessing, and it'd depend upon your shape. If my stomach was flat enough I might try for a holster pocket sewn into the inside just below the ribs? Similar to a belly band?

Chest rig. Carrying w/o a quality holster, just not smart.

Mossberg 500 with an extended tube.

Reminds me of ... what were they called ... thunder drawers ?