340 with no stamped numbers on it

Well what you know about it is what there is. Weird that the assembly information stamp on the left front is not there. Even as a no VIN stamp warranty block that would still be there.

What does he want to know about it anyway? You have already ID'ed it as 340 built after March 16th. It is most probable it was used in a 69 car as there are 4.5 months until the 70 production year start.