The value of this Hollenbeck drilling would be impossible to estimate without more details including good pictures. I don't know if these guns were typically marked as to gauge and caliber, so it might take a Cerrosafe chamber cast to determine that.

I noticed one omission on the list of rifle barrel chamberings was the .30-30, which was discussed in this 2018 Thread

https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=510830&page=all

I missed out on a nice Three Barrel Gun Co. 12 x 12 x .30-30 drilling at a Penna. Gun Collectors Assn. gun show about 1990. It was not a real high grade gun, but it was in excellent original condition, at a very attractive price. Unfortunately, I didn't see it until I had about emptied my wallet by getting some extremely great buys on four double shotguns. I think about it whenever I think about the ones that got away. What was normally a very large and crowded gun show was very sparsely attended that Saturday, because there was a home playoff game between the Pittsburgh Steelers and the Cleveland Browns.

A true sign of mental illness is any gun owner who would vote for an Anti-Gunner like Joe Biden.