I decided some expenditure was in order, so I bought a new coil from Partstree. With help from this site, I installed the coil and adjusted the flywheel clearance. Voila'. It always started and it still does. Now, though, it runs strong and no miss or backfire.
My thanks to everyone whose posts helped me figure this out. I would still be scratching my head and dithering over a $100 coil.