Ben,
You could pick up a Rem. 870 with the barrel you want and pick up an extra rifled barrel for a true 'minimalist' set-up. Set up the rifled barrel with a scope or red dot, whatever works for your hunting.
Sounds like the Kimber .308 is working out quite well for you, If it doesn't have one put a receiver sight on the Win. 30-30. The "Remington model 14 in 35rem with a good bore and a rough finish/bluing as a project" sounds like fun, but again... hold off until you find one with a receiver sight (they are expensive if bought separately)... This would duplicate what your 30-30 works for, Sounds as if you like to tinker so do it anyway.
Definitely get a .22LR, action and the brand something you like===> Win. Lever (out of production so kind of spendy), a bolt for accuracy... these days I would look at the CZ 457, or yes a Tikka T1X and a couple of spare magazines. Scope the Tikka T1X (for my use the Weaver 2-7 Rimfire is perfect, made in Japan, quality and on sale at Natchez shooters supply right now) or if a lever get a receiver sight on it. And shoot the heck out of it in the off season, hunt small game if possible in your area.
We've all bought guns for a "Reason", but our needs and circumstances change.
Trip a few and if it doesn't hurt, trip the rest until you get where you feel it is right... It will change down the road and you can change it up again which is half the fun.
YMMV,
Jerry
