part of me said sell the regular barrel 223 because the HB replaced it but when the HB needed work the reg barrel helped me shoot woodchucks.
I got the O/U for rabbits which I don't go anymore, my ML sucks and I found a better one today for 150 used but looks great. part of me says sell the other to pay for the new used one but part says keep both in case. I try and stay away from the used guns cause I end up buying a deal and say ill hunt with it like I have 4 deer guns now.
I'd sell the regular barrel 223. How often does it happen that you have guns being repaired and you really need something similar? One time in ten years?
Depending on family demands, I think two "deer rifles" is probably sufficient. Sounds like the Marlin 45-70 is just a fling.... if you have a hankering for one, do it. I would end up selling it after getting it out of my system. I had a strong hankering for a Marlin 1894 in 41 mag. Resisted the urge because I knew that I wouldn't shoot it much. Even went back to the store to buy it weeks later only to find out that they sold it. Fine with me. Saved me at least $500.
I have always wanted a 375 H&H rifle. But as the years pass, I know the likelihood of ever doing a hunt where I felt I needed it is remote now. It will remain an unfulfilled yearning.
The rabbit/small game shotguns are ones I got rid of since I wasn't hunting silly wabbits any more. I kept one for years just in case I migrated back to the sport. Honestly, even when I was actively hunting rabbits, I gravitated to using a 22 rifle and as I got older, added a 22 revolver for the fun of it. It was mostly about watching the dogs work than it was killing rabbits anyway.
If you want to get rid of the Mossberg shotgun, do it. Consider the Browning pump (which is a lot more expensive) or your basic Remington 870. I really like the Browning pump shotguns as they eject downward like the Ithaca's I grew up with.
I have a 870 police model now for "home protection". I suppose I could use it for hunting if I wanted to. It would also serve as a deer shotgun in the event I couldn't use a rifle for deer hunting (WMA's mostly). I have a smoke pole also for the same kind of scenario. Never really got into black powder stuff. It sits unused. Shot a few times. I have started using revolvers for primary deer firearm over the last 10 years and the rifles sit. Just loosing interest in the need to score. I mostly have a need to have fun.
As I mentioned earlier, I was a lot more satisfied owning higher quality guns in the long run. I replaced things like H&R and High Standard revolvers for Colt or S&W. Won't even consider buying third tier handguns any more. If I did, it would only be to help someone out of a financial bind. I would rather buy a new scope.
Thin out the low grade unused stuff and replace with fewer higher grade rifles, shotguns, and handguns that still meet all of your needs.