I came across an older book on productid brachiopods by famous British paleontologist, Helen Muir-Wood. Link: H. Muir-Wood and G. A. Cooper. 1960. Morphology, classification and life habits of the Productoidea (Brachiopoda). Geological Society of America Memoir 81.
The book was apparently in the library of German-American paleontologist, Curt Teichert, who edited many of the Treatises of Paleontology. Link.
Some of the brachiopods were, to coin a phrase, exhibiting derived convergent evolution with the mollusk rudists. Both were: elongated with one large and one small valve; and formed important parts of reefs.
Coscinarina species in plate 28 looked like rugose horn corals.
Proboscidella in plate 124 look like elephant trunks.
Prorichthofenia permiana from west Texas, figures 2 and 12 in plate 29, look like they are ready to swallow up Kirk’s Starship Enterprise.
This book is so unloved, someone was trying to sell another copy for under six bucks including shipping.