Heres a picture of a B14
There were two more Excelsiors in the 1932 senior that did not finish, ridden by Syd Crabtree and Harold Warburton. (From race information on the Manx Heritage site)
There was a picture of Syd Crabtree at the 1932 TT looking at an Excelsior fitted with a return sump J.A.P engine carrying the number 23 in an old issue of the motor cycle, unfortunately I dont know the date of this issue.
The bike that finished 17th was a B14 with a twin mag J.A.P engine fitted ridden by Dave Brewster, Mentioned in the article "Racing with Excelsior" in the Autumn 1986 issue of Calssic Racer.