Well, the new mirror glass arrived and it turns out I ordered the wrong one. The 2300 is the correct part number for the 10" mirror that wasn't used in the Corvettes until 1974, I just learned. The one I ordered was for the smaller mirror glass used from '67 to '73.
Here's the corrected link:
https://www.paragoncorvette.com/p-34...ror-glass.aspx