I have two Shellzone and one Zerex. As stated, they have never been opened. I have looked everywhere and made several calls. I've been told by all that full cans just aren't out there. How do I find out what they are worth? I'm working on the size of picture file.

To me full cans are of no more value than empty, as I am going to empty it when I get it. Sooner or later they will start to seep contents out. Just my opinion. Chris

I neither would place any "premium" on unopened cans of anti-freeze. The stuff will discolor lithography if it gets on it, and over time if it starts to leak, will take the litho off. I see lots of antifreeze cans with 1/4 of the lower graphics gone when they sat with the contents for years. I've emptied all of my Mobil ones that were full, for fear of future irreversible damage.
Darin

Yep what Darin said,this is why they suggest changing antifreeze in your auto. Even a empty antifreeze can will rust from the inside out.Collecting cans I put more value in a empty can and ask sellers to empty before shipping. Lot of work but you can protect from rusting away from the inside out by coating with gas tank sealer.
You will be lucky to get someone to value without a pic.