Wha....? Here we are nearly five years later (oops, almost said "down the road"...) You still have the truck?
Well, I did something stupid earlier this summer. I've got a '71 521 that sat for four years. Best advice on this thread is to pull the plugs & put a little oil down in the holes & hand crank it to make sure the engine hasn't seized. Well--I put in a fresh battery, turned the key, and even though I heard the starter kick in, it wouldn't turn over. So I rolled it down the driveway and let up on the clutch & the rear wheels skidded. Yep, seized engine. Rule of thumb is you got to start them every few weeks and drive 'em around the block or whatever, or your little Datsun will develop leaks and die. All moving parts will morph into one solid mass.