OK, I removed the face plate and looked at the OLED Display, but there aren't any markings on the front or sides. The way the header is soldered in, I can't remove the display without un-soldering the 16 pin header. The display face frame looks exactly like the form factor of a Newhaven display, either NHD-0420DZ-NSW-BBW or the similar NHD-0420D3Z-NSW-BBW-V3. Looking through the display manual, I can't see how you get a '12' in a single character position without creating a custom character. The '|' character is in the table where a '12' is not. You should be able to access the vertical line character without using a custom one.
It's usable as is, it just looks odd. Now that I know it's supposed to be a vertical line, I can work around it for now.
