A little piece of Engulfed Cathedral clarinet. Two tracks of Chamberlin bass clarinet. Find file 'DC Clarinet mp3.mp3' here:
http://launch.groups.yahoo.com/group/newmellotrongroup/files/I'm sure that the high octave of the Chamberlin bass clarinet is in fact Oboe. You can hear it in this clip. Kind of like the bottom end of the Mellotron cello voice not really cello. At least in that case, they used a similar sounding instument.
Clay