A while ago, my battery box was not supplying a full 9 V to the mic capsules (thx chris church) and was only sending a couple volts instead - I got a super wacky recording which had a decent amount of distortion.
I’ve heard from others that low battery levels can cause similar looking waveforms/distortion.
My waveform looked somewhat similar to yours but more extreme. I ended up doing a +90 degree phase shift (I know audition and Izotope RX both have the ability to deal with this) and it made it sound so much less distorted - the tape actually ended up sounding pretty great IMO. It did have some lasting distortion from the mics not being able to handle such high SPLs at low voltage, but it definitely wasn’t clipping since the levels were set low like yours.
From the looks of your waveform, maybe it could use a -45 degree phase shift or so? I’d maybe try messing around with that. Again, you would probably also end up with some high SPL distortion assuming the band played loud and that wouldn’t be fixed by a phase shift.
For what it’s worth, I don’t think the waveform you posted is too crazy looking.