For a quick way to get an idea of value and rarity, go to
eBay and search for the title on the can. When you get results, scroll down the page to look on the left column for a check box for "Sold Items" and click it. Then on that results page will be actual recently sold items that give a more realistic view rather than pie-in-the-sky asking prices that don't sell.
There are Solder Seal Radiator cans sold recently on eBay that have a background graphic of a radiator. Cans with graphics nearly always are more valuable than comparable cans with just a logo and lettering.
Condition is always a big factor. Scratches, rust, cracks, dents and other defects hurt the value for collectors.