4/8/71 mystery keyboard player?

[Paul Mcfadyen]

This is not a tape/CD request, because I know to use the Resources for Traders site for that.   Listening to 4/8/71 the other day, I weas struck by the fact that there appear to be TWO keyboard players. Although Pig's Hammond is v.low in the mix for most of the show, there are certain moments where you can definitely hear two instruments,   a) During Truckin' - organ is distant in left channel, with e.piano in right; both can be heard about 3:45 into the song... b) In Playing: Pig is playing percussion (guiro?) alongside Billy, whilst there is an electric piano in the right channel c) The tuning jam before BIODTL - at 6:52-7:00 on Loser you can hear both organ & electric piano tuning   To my knowledge, Pig never played electric piano on stage (it sounds like a Fender Rhodes or Wurlitzer) and I'm curious as to who the mystery player is - Ned Lagin was supposed to be guesting on Boston 11/21/70, although the tapes don't apparently bear this out; is this actually Lagin's Boston debut appearance??