2 Piper,
to qoute yourself...

"In the 1911 "ALFA" catalog is pictured a set of bbls of another brand with the short length stubs for fitting to a mono-block which are threaded. It was I felt a possibility Pieper used the same processs."

If that's the same as the August Stukenbrok catalog that shows a Record monoblock system, then I agree...because the OSH sidelocks on that gun are clearly Pieper...

I'll post a few pics so the other readers can follow...

I hope we're on the same page...