The German forum I linked to has a post concerning Plass that includes the text of another book -
""For Those who have arrived too late for the gathering. Prior to Skara we must gather off-shore to the west of Yew. Stores shall be collected in Varliin´s (der Name kommt öfter vor) hideout, and any surplus shall be taken to the nearby Abbay. Should the fleet need extra provisions, or should the forts be destroyed, Varliin will re-assemble all personal in his hideout, therefore not all supplies shall be loaded onto ships- Fate should not be tempted. If you miss the congregation before we embark, then make sure not to find us again. -- Plass"
Varliin was a key character in the "Dark Tides' storyline - you may find these interesting
UO Stratics - BNN Archives - Dark Tides - Drachenfels & Europa
UO Stratics - BNN Archives - Dark Tides II - Drachenfels & Europa
UO Stratics - BNN Archives - Dark Tides III - Drachenfels & Europa
However.. they do throw up a problem - it may be a completely different Plass, since in those his name is given as Plass Darakor and he is part of the pirates, rather than a 'Colonel' based in Minoc...