It's worth every effort to locate the car/owner and may take a bit of time. Most owners don't subscribe to the many sites that are available, but maybe 1 favorite like SYC, TC, this site, auctions sites, etc.
On another note, I located a '69 corvette 435hp alum. head engine in the Seattle area with it's engine number and oem broach marks. Before purchasing the engine, I made extensive efforts to locate the car, and I found it!! It was 2000 miles away and in the registry. I sent a special note to the owner, which was allowable within the registry format. No response. The owner already had the "original" engine in the car???? So, there was this indisputable engine with the heads off that anyone of average knowledge could verify as the correct engine to that body, which owner refused to acknowledge because it would have cost them a sizable chunk of change to acquire.........actually I wasn't going to hold him hostage, but would have sold him that block for $2500, just to put it where it belongs. The entire saga made me ill, because it made evident the ugly side of "numbers matching". My buddy suggested posting this all over the corvette sites to expose the car as a fraud, or at least the provinence of it's "numbers matching". I decided against it, and just let it lay. Not sure if that was the right decision or not, but I'm sure that someone else subsequent to me had the same decision to make on that engine, since I never bought it.