1964-D Quarter Repunched Mint Mark (RPM) Not In Wexler's RPM Listing

Its not listed because its MD. You are talking RPM, right?

MD? Here's what I use to identify Machine Doubling versus Hub Doubling. The former is common the latter is not.

Machine Doubling
1. Always cuts away at the normal thickness of the devices affected. This in effect makes the device that stands out in relief thinner than it should be.
2. Has a step-down appearance to the 'doubling' which lacks character, boldness, and thickness.
3. Never shows 'notching' at the corners of the devices because the original die used to create them does not have this notching.

Hub Doubling
1. Always has extra thickness to some degree - in other words, the doubling never robs from the normal devices to cause the doubling.
2. In many cases 'notching' shows at the corners of the devices where the overlap in hubbing occurred. Just look at the picture, find 'notching', and this statement will be very clear.
3. Hub doubling actually creates a secondary 'set' of devices, which is apparent when looking at the doubling. It has relief - character. Machine Doubling only flattens parts of the only set of devices that exist, because there was no doubling in the die that created the coin.

Having said all that, I read further on Wexler's about RPM and gathered that since mint marks were hand stamped onto the working dies, that they had a different standard?

Thanks for any further education on this matter as I'm trying to focus my attention on the higher value error coins.

Here's a closer pic of the mint mark

Bluvase, descriptions are fine, here's what happens, especially on harder metal coins. Since the mintmarks are hand punched into each working die, the "depth" of the device may be greater than other design elements. This can cause a catching of movement more than the others. Their is some sharp angled MD around there. The MM shows classic shelf like slide doubling of MD.Hence, isn't listed.

Good question and great answer. I always appreciate a brush up on that subject.