Success.
Perhaps the ambient temp of 18 F helped a bit… ? And yes, I did manage to keep the salt from the garage floor off the tools.
The hammer never had to come into play.
The tool: T&E Tools 1 ton two jaw puller, $33 on Amazon. And the official Campy PT puller plug, $25 from Ben @ Velomine.
BTW, if anyone really needs the official plug, the Campy package actually contained two of 'em. I'll send the unused one out to you for $12.50 shipped. FWIW, there are alternate options that probably work as well.