Life with Unix says: Wrote find, cpio, expr. Added named variables to shell. Major contributor to PWB.
A Research Unix Reader says: Joe (Joseph F.) Maranzano of the USG and Dick (Richard C.) Haight of PWB became de-facto adjunct members of the research group. Haight contributed find, cpio, and expr, all in v7.
By personal communication with Dick Haight we know he also contributed popen (in v7) and the bs programming language. The latter appeared in PWB/UNIX 2.0, UNIX System III Release 3.0, System V, and many licensed derivatives.