I;m bored and laid off so
1 unless you know refer work start from scratch they still make parts, old unsealed refer parts are junk unless you know how to clean and check them.
2 adjust shift linkage when tranny is in low 1st, loosen the linkage and manually go thru the gears to 1st with your hand at the trans tighten the hardware. indicator fully seated? just pushes in, tilt column has weird long pointer, bent? Battery loose? jams up linkage at firewall. Dead cat, lost tool?
3 We all suffered thru that the hoses are old and gaskets go bad, They were never meant to last a lifetime.
4 Look at other cars trucks , notice when they start up water and water vapor comes out, the exhaust heats up attracts moisture it gets cold and condenses.When a vehicle starts the exhaust system is cold and cannot keep the moisture in gasses suspended. An old rusty exhaust can be worse. Look for loose clamps bad hoses at the heater core, I've been fooled before it drips inside on the floor