My tool kit has evolved over the years to the point where I've got it boiled down to the contents of a canvas military tool bag. Highlights are a metric socket set and a half-inch drive, a 17-mm male Allen socket, two crescent wrenches, needle-nose pliers, a Leatherman, one standard and one Phillips screwdriver, a pair of valve-cover gaskets, a belt, a throttle and clutch cable, fuses, a brake-light bulb, a crimper and butt-connectors, a test-light, postal tweezers, a wire bread-tie, a telescoping magnet, pop-rivet gun and rivets, a couple Zip-ties, a Petzl headlamp and a spare key.
There are three spare quarts of oil and rain gear in the car already. For Carlisle, I usually bring a jack, a tire-iron and a jack-stand or two. Some of the guys bring blue painter's tape for weather-resistant sealing on their windshield seals, and you might see the odd Bowie knife for the 'what-if' scenario.
If you're traveling in Maryland, leave the pistol at home. Bad idea.