Mid-1975 album mixing at Heider's

Can you tell I am going through some fragments?

Anyway, this little tidbit, from August 1975, has me a bit puzzled. Which album is this? I just don't recall any Jerry-related work at Heider's at this time.

The Grateful Dead might have been referred to in this way at this time (they had played the SNACK Benefit in March and the Bob Fried Memorial in June billed this way, IIRC), and the timeline just about works for Blues for Allah, which was released in September. But I don't recall any Heider's connection (though I see from deaddisc that Stephen Barncard is thanked in the liner notes). It says that the album was mastered at Artisan Sound Recorders, an outfit with which I am not familiar. This seems like the likeliest candidate, to me.

Reflections seems unlikely, both because this is too early for mixing and because according to Matt Scofield's amazing resource (see link on album title) it was mixed at His Master's Wheels.

Just not sure.