Howdy Back:
Those marking don't help much. Take the cover off and tell us what you see. Are two advance return springs visible? If they are it's a Load-O-Matic. If it is from a '67 engine, then it is likely a Load-O-Matic type point distributor. Is the vacuum advance cannister still attached? '68 was the 1st year of a more performance oriented distributor. They have both centrifugal and vacuum advance. The centrifugal advance return springs are not visible from the top. They are under the stator plate. The vacuum advance return spring is built into the vacuum cannister housing.
I hope that helps with your iding it.
Adios, David