* Update at this stage is that I have fixed the Right Ramp Top Flasher Light (discovered a wire had been dislodged from the plastic plug)
* And I may have discovered a possible clue relating to the 'CHECK SWITCHES' alert for #34 and #35. I cross-referenced with the Switch Matrix Grid Chart in the game manual and it has those two 'Not Used' switches associated with the Grn-Blk wires (on the Drive column).

I then searched through the wiring under the playfield and discovered some of that associated wiring may have been tampered with by the previous owner.

i.e. as can be seen in the attached pic, there are three Grn-Blk wires soldered together (with no insulation) plus also another single Grn-Blk wire looks like it has previously been slotted into a plug but now isn't (some tape had been put over the area where it had previously been attached).
I have also included a pic from further away so any X Files owners can see the location of the wiring in question, and can maybe have a look under their playfields for me to double-check how it should be?

Many thanks for anyone who can assist.
Best regards,
~ Mick