There's a picture of a twin carb weslake on this German website.
http://www.bahnsporttechnik.de/
which links to this
http://www.bahnsporttechnik.de/body_weslake.html#Weslake
scroll down, just before the v-twins is a picture of an Otto Lattenhamer Twin Carb Weslake
Yes definetely two different riders, in fact it's Bill Andrew , no 's' at the end, and as Sandman says he was quite small and actually doubled up as quite a good national hunt jockey while riding in this country.