Some free things that you can do, would be, To do a complete PMCS (Preventative Maintainence Checks and Schedule) For you non-military people.
make a list of things that are in need of repair, or replacement. Some stuff is easy, other stuff is harder, but no big deal. One other thing I would do, IF you know your vacuum lines are in the right places, See if you can get some model paints or even finger nail polish (Trust me) and put a small dab of paint on the hard line then one on the hose, this will help to prevent any mix ups and a cheap way to keep things straight.
Once you have the list start going through and make it into a constant check list that can be used for daily, weekly, monthly, bi-monthly, and yearly checks, as well as a place to enter your mileage for your oil changes, tune ups, and mile sensitive maintenance.
This will give you a baseline to keep things simple and give you a priority list when you have the money to repair/replace any items that need attention and put let you decide how and when to handle them best. I don't know if anyone else here has such a list, but there is a good PMCS that the army used for the HMMWV's that would be pretty close to what you could start with.
you could also work on your checking your electrical, making sure there are no messed up wires or any thing that could be a hazard later. thankfully electrical tape is cheap. and there are plenty of wires to inspect.