I was worried about buying my car too at the time so i took my mate who is a mechanic. He could only see the basics ie wierd noises, panel damage etc. Good idea to try and get somebody who actually knows about skylines because my friend didn't see a couple of things. EG the aircon belt was missing ended up costing 1000 for complete new system. And the timing belt soon after. Car had 60000km on it when i bought it but somehow dont believe it. As i said you did the right thing by getting an RACV check but if you know someone who knows about skylines get them to check it out.