Vintage Nikes

Whilst pottering around the offices of a certain defunct clothing label I stumbled across these. I believe what I have found are a Nike Cortez (blue) and a Nike Waffleracer (green). Both are left feet and both, I believe, were samples found in the USA on a trip. Either way I know they are old, and I am guessing worth a fair penny, its just a case of how much? The only concrete detail is that they are from before the early 1990's. They are both made in Japan which i think narrows it down slightly. Around 15 years ago a different colour-way, but still a single left foot, was sold to a visiting Japanese buyer for some several hundred pounds. That is why I pulled these out of boxes and boxes of samples and that is why I have a feeling these are worth a fair amount, hopefully only accumulating worth over time. I guess one needs to seek an expert on these sorts of matters