383 Harmonic balancer question

It may just be an optical illusion, but the ring on the bal hub looks thicker towards the bottom......which would require those holes to try & balance it. Usually the ring gets drilled to balance the unit, not the hub.
Correct, typically the inertia ring is drilled to balance the damper assembly in production. Drilling the balance holes at a larger radius gives you more balance correction. As GTX John stated, those balance holes may have been drilled in the damper hub to balance the rotating assembly, has merit here. 65'