A. J. Musselman Incorporated in Chicago, USA made or marketed at least a Power Detector Tube Model 5PD. The box declares "Detector only and states Fil. Volts 5, Fil. Amp .25 and Plate Voltage 45. It has a "cussion base" for being "Non-Microphonic. We beieve that in function the Tube-Type 5PD might be quite similar to the RCA UX-200A tube.

We don't have the picture yet about Van Horne tubes and Musselman.
Gerald F.J. Tyne wrote on page 359 in his book Saga of the Vacuum Tube): Musselman 1925: Made by A. J. Musselman - The Van Horne Co., Franklin, Ohio. And on page 364: Van Horne 1926, Made by the Van Horne Company, 1004 Center Street, Franklin, Ohio. We did not find any tube type of them in this book.

Interesting is the address we find on the box: Chicago, not Franklin, Ohio. And: If you look at the pictures for the Van Horne tube