That pattern of wear is consistant with the
oil pump being run under a strong preload from the distributor shaft. After you press the gear off, drop the dist back in, clamp it down, then turn it. It should rotate with only minimal resistance as you are turning the
oil pump too. I bet it will have more than minimal resistance.
Oil pump drive shaft is too long (or you could say the broached hex drive in the dist shaft isn't deep enough)