Make me spill my beer

You're asking about the Tweedy tour? Sure there was "merch"! There were great posters for both Marfa and Austin shows. Also, Ballroom Marfa, the series/organization that brought Tweedy to the Chihuauan desert, had its own poster for sale specifically for the Tweedy show.

If it's the same one they used last night in San Antonio, it might be Satie's Gymnopedies. But I'm not sure. Music school was a loooong time ago.