London Track number 77 is not a very detailed cast. Only three toes are visible, and a slight heel impression is evident. The heel impressed only about one cm into the substrate, and this feature is more visible in the daytime still than in the photos of the cast itself.
The striations on the toes are of some interest. They are not parallel, indicating the possibility of independent toe movement. If a fake prosthetic was used to make this trackway, it would be expected that the toes would show parallel striations since the digits would be all connected to the same surface. The close up of the toes in the gallery below shows this feature best.