Remember the old saying "If it works don't fix it." It will save you THOUSANDS of dollars in parts you don't need. If you were building a hot rod that would be one thing, but if you just want to drive it fix what needs to be fixed and leave the rest alone. I'm not saying ignore problems, but you don't need to upgrade every last part to 2013. When you have more money you can always upgrade it later but trust me it's a lot of fun driving an original
That being said there are some upgrades that are well worth your effort. You mentioned converting to 12 volt, that I would definitey go ahead and do. Converting the front to disc brakes really isn't necessary as it won't go fast enough to need racecar-like stopping power. But if it makes you feel safer by all means do it. I would add seat belts too and worry about the interior last. One more upgrade that is definitely worth your time is adding in reverse lights, my 63 doesn't have them and I sure wish it did.
All in all it seems like you have everything prioritized very well and have a good vision for your project. Most importantly no matter how discouraged you don't give up! Keeps us posted and good luck!
