On P-3s, tell your IFT to do this:
Get adapters to go from S-Video (out of the laptop) to RCA, to Coax and then to Triax so it can go into the VDC. (I chose the EOW input so that flight could watch the movie also and the tube could see the video while the TMS was up).
As for audio, I'm sure the IFT will know how to rig a handmic to hotmic and wire a headphone jack into that. (The only bad thing is if you have a bad DCI/DAI in your ICS, it can screw up your laptop headphone jack. I learned that the hard way).
Just put the laptop across from SS3 and run the video cable right to the VDC and the audio through the rack to SS1 station's ICS. (Make sure your acoustic guys know not to switch the controls to all or you'll be blasting the laptop audio to everyone).
If you have any questions, just PM me.
Hope my advice helps on those long transits.