Earles forks on a BSA makes more sense (good I kept the 5% of doubt!!)

Other images show a AJS porcupine and a couple of Moto Guzzi...

In the Senior the only race I can find with 2 Guzzi is 1954
Which was made number 27 Sandyl-Winsch with Earles forks ... on a Velocette but this isn't a Velocette!

Curious