Since you are into history
Shotgun: Winchester 1897 Trench gun, outfitted with bayonet and vented heat shield, 20" barrel, Mossberg 500, Remington 870 Wingmaster
Revolver: S&W Model 27 (.357Mag), Ruger Single-Six Convertible (.22/.22mag), S&W Model 10, S&W Model 19/66, Ruger GP100, Colt Detective Special
Pistol (semi): 1911, Browning HiPower, CZ75, Walther PPK, Beretta 92, S&W 5906, Ruger MK series, German Luger
Bolt Rifle: 03A3, VZ24, K31, German K98, Mosin-Nagant, Lee-Enfield .303, MAS 36, Springfield .30-40 Krag,
Rifle (semi): HK 91, FN FAL, MAS 49/56, AR10, M1 Garand, M1A, AK47, HK MP5, Ruger 10/22, Marlin 60, PSL Dragonov,
Lever: Winchester 94, Winchester 1892/1894, Marlin 336, Marlin 1894, Savage 99
There are many more I have not listed as great guns for a collection.
A lot of your next option depends on budget, but a lot of good collector firearms are getting more expensive each year.