Yes. I'm not really "au fait" with American racing of the period, and I took the website's name as correct. I've now found far more info on the car, and the owner's name was indeed van Meyer.
He originally raced and hillclimbed a special which was Pontiac-engined, but it became obsolete, and he arranged for Bill Sadler to rebuild the car in more modern style. This was the result - sort of. The Sadler-Meyer was still powered by the Pontiac, but a subsequent owner had the car restored and re-engined in this form. The source of my potted history claims that the Chevy has been bored to 339ci.
I attach a photo of the Sadler-Meyer as it should be, Pontiac-engined and as made by Sadler. The car in the puzzle is what might be termed a later version.