St John's Top 5: Shrewsbury Tower grotesques

This month we look at drawings of the stone carvings on the Shrewsbury Tower. The tower was restored in 1959-1960.  The original carved motifs were severely eroded and it required great skill to provide new figures similar to the old.  J Ison of Girton completed the stonework from designs by Mrs DF Kramer. Alec Crook in his book 'From Penrose to Cripps' claims that the two stone faces in the string course north of the tower are meant to represent the Bursar for Buildings and the Architect in charge. Can you put a name to the face?