thanks for the input 500nitro and herrdoktor,
one of the things I did find out about the 221E is that it has been built for a long time[ at least 80 years ] so it has stood the test of time. Also from a story in the double gun journal [ issue 3, 2009 ] and a pic or two I found on the net, it looks as though they are indeed made without any bolting arrangement that utilises the bottom barrel lugs, relying on the kersten bolts only.
All will be revealed in a few days though and if I grab the bugger I'll post a few pics.
regards,
Underlever