FYI: Ebay seller with a reel of Quad Tape. Mentions that it was dub stock (plausible as the reel is "three-quarters full"). Claims tape has "unknown content recorded on it". http://cgi.ebay.com/Ampex-148-High-Band-2-Quad-Video-Tape-USA_W0QQitemZ320459617012QQcmdZViewItemQQptZBI_Blank_Media?hash=item4a9ce1b2f4#ht_2998wt_941