Posted by Len Provisor on May 13, 2019, 11:50 pm, in reply to "BHCR"
RHR or RCHR is Red Hard Rubber or Red Chased Hard Rubber. Some rare pens that are chased (engraved patterns) in a mix of red and black such as mottle or woodgrain have been seen. See article on Home Page about chasing machinery by Thomas Neureither.