Well, I appreciate all the information and suggestions.
I plugged it with a 'gooey worm' (nice description, Wayne). The hardest part was reaming out the hole. After that, it was pretty standard- coat with contact cement, insert, pull out quickly (and hope for the best). After one day, it still seems to be holding air just fine. No change on the gauge after 24 or so hours.
I think a Dynaplug would have worked also- the tire was pierced by- of all things- a square nail. I have no clue how that happened! My house was built in the early '70s.