Several examples are here Bill
http://www.picturetrail.com/sfx/album/view/18015717
I am of the opinion (which is worth nothing) than some mis-matched tubes, esp on higher grades, were salesmen's sample guns.
The rough forged tubes were paired in Belgium and wired together for shipping. It is very difficult to identify the pattern in both rough and 'in the white' tubes, and mistakes could have been made in finishing and joining tubes. I can't imagine they slipped out of Meriden by accident however once the barrels were colored.
Threaded Mode