I made the final decision to use brass brads to mark the 1 inch increments.
there are pros and cons to all the options i was considering.
pros = allows metal to be present outside of the head
= the reflection of the material sticks out the measurements
= brass adds to the vintage look, without being vintage at all
= easy to replace if the odd chance they come out.
cons = although the brads are glued and below the wood plane, the could come loose in time.
(i have done this before and never had one come loose. being set just below the wood, it wraps itself around the end of the brad and the hand through use burnishes it into place)