On the way home from an appointment I didn't know had been canceled, I decided to pop into the antiques mall. There were a couple of bins of 78s at $2 each, so I dug through them.
Among the Deccas, red label Columbias, etc., there were a few good '20s labels: Emerson, Regal, Clover, Banner... when, lo and behold:
A TRIANGLE!
I only had one, that I had found by accident many years ago: now I just doubled my total!
This is a rather late issue for Triangle, from 1925. I believe this is a Joseph Samuels studio group, recorded for Paramount and released on a number of minor labels.