Welcome to Coin Talk. None have been found to date. I dare say your coin may be afflicted with Machine Doubling of some type, photos do not allow any confirmation. http://www.varietyvista.com/15 Golden Dollars/Sacajawea Dollar Varieties.htm https://www.error-ref.com/machine-doubling/
Try using a different source of light and check again. I have seen this effect before, and it has to do with the ring light on usb scopes. When I suspect doubling, I turn off the ring light from the scope and use a pen flashlight to eliminate glare and false doubling. This method will help a lot with notching on lettering too…imo…Spark
You have to be careful using microscopes with LED's, it can make the letters look like they're doubled when they're not, it's actually reflected light. I call this reflection doubling. Here's an example of reflection doubling:
The correct numismatic terminology is Doubled Die.. not double die as you stated in your thread title. That is incorrect and something totally different. Here is a link which explains Doubled Die https://doubleddie.com/58222.html Your coin is not a Doubled Die variety.. Looks like die deterioration doubling to me which is caused by a worn die. Nothing to do with a true DDO variety.
