As said the auction claims the holes are factory. I would think that the kind of people who might actually buy one of those might have a competent gunsmith find the appropriate size and length screws to fit the holes. People in my circumstances would grab the can of bondo, a spray can of RustOleum and "git er done." Which is why the folks that manufacture items like the Champion, the Arnage, or the Round Action Sidelock intentionally price them out of the reach of guys like me.
Then once every few years some guy of my circumstances wins the lottery. And the gentlemen who represent and craft bespoke guns, bespoke suits and bespoke automobiles grit their teeth and wince in pain..