In my search on Hallmarks I found The Ken Hawley Collection Trust which is part of the University of Sheffield. In the trust they have 10 "Open Razors" which they date and describe at length.

https://www.shef.ac.uk/hawley/collec...zor-intro.html

In one description the WR mark is described: (I italicized and bolded the text.)

DATE - Joseph Rodgers and Sons were at No 6 Norfolk Street from the early years of the 19th century until the mid-20th century. WR is William Rex, William IV, 1830-1837

William Rex. Now I understand the R.