I think the door locks work from an electric pump under the rear seat, not for sure.
Getting the vac systems hooked back up should be fairly easy, the plastic lines are color coded.
Green is the supply for the AC. Should have a one-way valve on it, supply is from a T or Y going directly to the manifold.
If you seat back locks, I'm not sure what the color of the line is, but it will have a one-way valve and be a different color than the climate control (green).
Door locks, if operated off the engine vac, will have a yellow plastic line. This one will have a "T" fitting after the one-way valve going to a tank in the fender. Also a yellow line.
I suspect the headlight level control will be a white line, but I'm not sure.
If there is enough plastic line left on both ends of the melted portion, you can simply splice them together with plain black rubber vacuum line. Fit the check valves so that they hold vac on the passenger side.
When you test with the MitiVac pump, you may have to pump quite a while if there is a vac tank in the system. May take 30 or so pumps to get vac.
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!