It looks like you used the INF file from the OS/2 toolkit (GPI Guide and Reference) as the source material. But some links are missed, and they are just plain text.
For example, in GpiSetCharBox, there is an item Graphic Elements and Orders. In that page, there is a link to "Set Character Cell", but in the EDM/2 Wiki web page, this link is changed to plain text.
There are many Gpi functions -- it looks like you did a lot of work.