Yes, I have a frame and engine number to cross reference, as it was listed on an old registration document that we have from when my grandfather owned the car. Yes, very much like finding a needle in a hay stack... I've "checked out" a few cars over the years, and none have them have proven to have been his. Unfortunately I do not have new information. The car was in quite good shape when he owned it. It had been restored during the time that he had it, and carefully stored a since then. I only remember the car being out in the daylight a few times during my childhood, and one of those is when I rode with him in it as we drove in a parade in Paxton, IL. That was probably 30+ years go now.
If it is located, I would be happy to discuss the possibility of purchase from the owner if there is mutual interest in that, but I understand that it may not be the case. In which case, I would respectfully ask to be contacted if the car is for sale at any point in the future. Many years ago I saw a rare car that I was interested in, and I simply put a note on it asking to be contacted if it was ever for sale. A few years later I was! I ultimately lost out in a "name your best price" battle as that model of car was surging in popularity at the time, but the point is that I respect another's privacy, at least as much as I value my own, if not more. I have considered purchasing another one similar to his, but at this point I'm trying to find his car. I don't advertise my belongings either, and am protective of my vehicles as well, so can understand that sentiment also...