Try adding the line - <include>eq2ui_tkingceltic.xml</include>
in your eq2ui.xml. I also quit playing for a long time and just recently came back. (I was thinking of finishing this mod someday). When i read your post i took a look at the zip files for the three tking pieces i had made and noticed i only included a copy of the eq2ui.xml in the group window. Without the above line you will not have any border
sorry about that. I will probably continue this mod and get something more complete posted in a few weeks.