You are surely correct that by today’s “hindsight” style classifications, this face is better described as a “text” rather than a “blackletter,” which is rightly reserved for heavy-face German-gothic forms.
The design for MSJ Circular Black was patented by Ihlenburg in March–April 1883 [USPTO D13848]. The (maximum) 14-year term expired in 1897.
Oops! Sorry, I had forgotten to add this beauty to the progress chart.