Late breaking update:
I just contacted Tom Roster, the guru of no-tox loads for wing shooting, and asked him directly if I was better off shooting bismuth, opening the choke, or having a "steel safe" choke installed by Briley in this original Winchester Heavy Duck.
He said "none of the above." Just shoot steel or Hevi-shot through the factory full choke, just taking care to not use shot larger than BB or faster than 1400 fps. I was sure surprised!
Regards to all,
GC
