I have a compact, bright LED flashlight 4" long with a "tactical" bezel. For my money, a classic 3- or 4- D-cell Maglite is more anachronistic, more better self-defense.
...and the LEM trigger is even smoother than my Colt.
If you had to rely on a cartridge available 100 years ago-38 Special, 38-40, 44-40, 44 Special, 45 Long Colt, 45 ACP-or 12 gauge. You'd do just fine.