Does anyone know what kind of locks were used on Stephen Grant's guns such as the one on GI below?

https://www.gunsinternational.com/guns-f...un_id=101162486

Here is a "T. Newton" with a very similar lock patttern:

https://www.guntrader.uk/guns/shotguns/newton-t/side-by-side/12-gauge/181002184434001

I don't recall seeing these locks anywhere except Grant's guns. Did he hold the patent on them or something? Or is it likely he made the Newton gun?