Vetlel is much easier to like when he is not waving his finger around and being a proper prat, if he can show he can be gracious winner as well as a loser he would have my support.
Depends on the people that own the car before you to. My Skyline was imported by a family member who lives in Japan and it has genuine low mileage, and completely stock, the only issues I've had are headlight switch and the window switch. Not bad for a car 1/4 of a century old!
left and and right headlight are on different circuits, and the switch issue is intermittent, so makes it a little difficult to diagnose.
You will need a little pointy hook tool to remove to circlip that hold the spindle of the switch to remove the unit from the dash fascia.
Probably the switch on the dash, take it apart and clean the contacts, make sure the little black fingers are not melted, and ever so slightly stretch the springs. or buy a new one for $160
what about the in-tank lines? the outside ones have inner and outer layer, the inner is impervious to most fuels, ethanol include, but I thought the outer layer was not?
Try going to Amayama, use the russian site to find parts as the english site does not have the diagrams, some prices are hard to beat...
http://nissan.epcdata.ru/skyline/
http://nissan.epc-data.com/skyline/