sounds like the '48 would be cool and unique, but I think the truck would be easier/cheaper finding parts for and probably cooler to cruise around in as an 18 y/o. the original question though i guess was is the '48 repairable and from the description it sounds like the answer is yes. able to be done by you though is probably a more difficult question. it sounds like your grandfather would be willing to hang on to the '48 for you once you pull it out. maybe store the '48 for later on and save the truck now. i would say you can't go wrong tinkering with either one though whatever you decide...