Just a brief reply, because the Beta Blocker heart-med is still sapping my energy. LaGold's shell is a CS Marshall Arsenal 4-Stud Plate Sabot shell, as shown on page 213 of the Dickey-&-George 1993 Edition.
Bart, the Atlanta Works Read shell you mentioned has a copper Read ring-sabot. LaGold's photo shows his shell has green-patina copper all the way across its base, so it cannot be a ring-sabot.
Regards,
Pete