WOW , that's a tall order , top down or bottom up , doesn't matter , but like anything else , body , engine , driveline , look for rust under the fenders , cab , windshield frame , cargo body . Check for obvious oil/fluid leaks and CONDITION , brakes , lights working . Check front axle boots , all backing plates for leaks . What has current owner done to the vehicle ? tire condition ? . Engine/transmission , operation condition , clutch operation . We can go on and on , read the Military Drivers TM , it will help a lot . Not to pry , but a lot depends on your mechanical ability , try to take some one who has knowledge of MV's even if you have to pay for his time , money WELL SPENT . good luck on your quest , bob k