Use a timing fixture to set the points instead of a feeler gauge.
http://www.franksoutboardtools.com/timing-fixtures.html
Line the coils up to the mag plate bosses using a coil locator ring.
Points should be polished up shiny, and then de greased with acetone or lacquer thinner. A worn bushing on the mag plate will cause eratic spark timing, so to get around that use Atom ignition modules (if you can find them) in place of the points and condenser. Make sure plug wires are good and have good solid non corroded connections at both ends