When I sold the shares, various lots were displayed so that I could choose which lots to sell. Assuming the “cost basis summary” I now have represents the information displayed when I sold, all lots were labeled “SpecID”; and all covered lots and some noncovered lots had “date acquired” and “cost”.
Although I blindly chose without regard to ID method or date acquired, I believe I am bound by my choices at least with regard to the covered shares.
After submitting my original post I realized it would be to my advantage now to apply Spec. ID to the NONCOVERED shares, but differently from what the “cost basis summary” shows for some of those shares. Second best would be to use the Avg. Basis method.