In his book he mentions this as the largest his arms ever got, around 18” which look huge here. Great shape and shoulder width.
I have his book building the Classic Physique & it´s a great read, infact one of the best books i´ve read on Natural training.
It´s amazing how he got in shape for films as he wrote he never trained all year round.
some people say he was on the juice but i don´t believe it looking at his physique.
His incline curls were special in that he fixed a bar onto the incline bench so that when he curled his arms were motionless like using an arm blaster but on an incline, also he used an off set grip.