Seemingly new-to-circ OAITW show via Matt Smith and the Pacific Northwest crew running at Lossless Legs. Fun stuff. Richard Greene is there, which puts it to April-May '73, in all likelihood. It's also in a goodish sized hall, not the Keystone or Boarding House or whatever. My own guess is either Santa Barbara 4/12/73 or one of the Oregon shows in May (5/8 or 5/9), but that's just base speculation.
Pat Lee suggests that the fact that the reels were on BASF tape stock is consistent with the Santa Barbara soundman stuff (cf. 4/20/74, 4/24/74 GASB shows that Will Boswell also had on reel from that source). Funny thing is that the 4/12/73 wasn't even listed on TJS until it was added based on info from Richard Greene, and now this tape cames along that might well be it.