I think the staple to rivet change happened during HJ. I can't remember what exact difference there is between HQ and HJ. HJ had canister holes from Jan '75 plus rear wheel lock control introduced so they have another hole (which HQ might not have) for the canister when it has to move to clear the lock control thingy which mounts in the canister's spot.
Of course there is all the holes for A/C on the pass side guards, not sure if these were simply drilled or punched. I'll check part numbers.