The books that you can get at any parts store have the vacuum diagram. Are you not getting any vacuum at all? What kind of oil did you find in the lines? If it is brake fluid then your power brake booster has possibly gone out. If the diaphram goes out in the booster, it allows brake fluid to get sucked into the vacuum line. And if this is the case, the brake fluid can have a caustic effect on the vacumm lines going to all of the vacuum powered accesories (power locks, vents, ignition shut off).
Take a good look at the fluid that was in the lines. The vacuum is not too complex on the vehicle but can be an expensive repair. Fortunately, there is a rebuild kit for the vacuum pump. If it is the brake booster, THAT could be a very expensive repair.
83 TDT 110K