First round of cleaning this morning yielded the engine suffix crayon marks. Pulled the valve covers afterwards to find the properly dated 461's along with the original "O" rocker arms.
On a different note, have you seen a remanence of paint on the deck like found here? I cannot say that I recall that. The rest of the paint on the engine strikes me as original (obviously with the crayon marks on the head).
I neglected to answer the other question Bob had in his post "will the car be for sale?" Yes it will. If anyone would like to know more about the car, feel free to reach out.
Thanks for the continuing interest!
Tim