Oh ya, another gem. Welcome to Steel Soldiers and all the challenges that come with the X in experimental GMC.
If you do a re-build or a restoration on it, start a thread with a title specific and unique to the truck, here in the Early Deuce Forum and get us pictures. (Something like 1952 XM211 454 with a blower, twin turbo and 411 gears)
If you're not planning on starting a build thread then just add your pictures to the "Unofficial G749 picture thread" located in this, the "Early Deuce" forum.
Either way it'll be good to see a barn find, congratulations.
Typically, anything sitting for that long will need lotsa love before firing or driving on public roads. Wouldn't want a plugged rad, mouse nest, dirty old fuel, water in diff, insufficient fluid levels, frayed wires or an old seal ruin your day.
Let us know what we can do to back you up.