That HPI I was talking about (#90) has a few pages on what to look for when buying a new Skyline, it covers ignoring the kays (because its a fact of life that the Japanese love to "knock the clock", how to tell for telltale marks of coming from a Japanese junkyard (where the slingmarks are), where to look for the oil leaks, where to look for rust or rust repairs, getting the feel for the mechanical condition by driving it (what to look/listen for) etc. and is well worth the read if you're interested.