Jumping a tooth would be very unlikely. What is more likely is that the distributor was removed and replaced one tooth off. This had happened to a truck I bought used. It can be corrected easily to restore your full sweep from advance to retard.(If that is what happened) Chain stretch can also affect timing.

America's first fourwheel drive was built in Mankato, MN by Ernest Rosenburger in 1908 who founded Four-Traction Auto Co. on Hickory Street. The company though successful closed in 1913.