Looks like you got a great deal, even if you eventually have to refurbish practically everything. We got an '84 Burro
for about that price and started fixing things right away. Just start with the things that will make it safe and campable and start using it so that you "bond" with it and are encouraged to tackle the ugly jobs. After camping in it a few times you will develop your list of priorities. Usually this list is different than what you thought at first.
We ended up doing serious work on every system in our Burro
, including replacing the flooring, but we used it all along (except when the frame was off and the floor out.
So, you can live without a water tank for quite a while and still enjoy the camper, but the door needs to be secure. The hinges can be quite ugly and still function adequately, but the mounting area on the shell needs to be secure. Most of the FG campers have a wooden reinforced door hinge area which is glassed over on both sides. Often the wood is rotten inside and the mounting screws are rattling around. If this is the case then you will need to cut away the FG (on whichever side is easiest to repair cleanly) and glass in a new wood support block. Sometimes the lower support area is inside the lower base cabinet in the camper and you don't need to make the repair look perfect, just strong. But you will figure out these tricks as you work on it and get a feel for what matters.
One point to keep in mind. Try to learn ASAP if a part is replaceable or if you will need to repair what you have... Your hinges may not be available but similar ones may, but they will have a different mounting pattern. Your tank does not appear repairable. Polyethelyne and polypropylene-your tank- cannot be glued but requires "plastic welding" which is beyond most folks ability. But replacement tanks are readily available. Not in your exact size, but close. Industrial supply houses usually have these in many sizes. You can be creative with stuff that does not show.
Good luck with it and keep the questions coming as there are folks here with experience in practically everything that you will want to do to your Boler
. I never would have done some of my repairs on our Burro
without the help of folks on this forum.