Hi Albion,
the link between the OC and Anglican Churches is the "Bonn Agreement" dating from 1931. In this agreement all member churches of the Anglican Communion and the Old Catholic Churches of the Communion of Utrecht declared full intercommunion and interchangeability of priests. In 2006 there will be a major celebration of its 75th anniversary in Freiburg (Germany) with the Archbishop of Canterbury and the OC Archbishop of Utrecht. The fact that you did not find any mention of the Bonn Agreement on any site may be due to the fact that the OC Churches are quite small and not too well known. You'll find the Bonn Agreement mentioned on the Anglicans Online Site under "In Full Communion". I found the text (German and English) on the German OC website:
http://www.alt-katholisch.de/oekumene/bonn_agr.htm#ba
Recently another problem has occured: In the states the PNCC (Polish National Catholich Church) was the official branch of the Utrecht Union of OC Churches. After most of the OCs have started to ordain women to the priesthood, the PNCC has left the Utrecht Union, so that there is no official branch of the Utrecht Union in the States at the moment. The Utrecht Union has started talks with the OC Church to which our Father Rick belongs to explore the opportunity to make them the official partner church of the Utrecht Union in the States. (Please correct me, Father Rick, if I am wrong).
There is a thread about the Utrecht Union somewhere in the sticky department of this forum.
Greetings
Bonifatius