Come By Chance is a town on the Avalon Peninsula in Newfoundland and Labrador, Canada. The refinery was originally built and dedicated in 1971 to 1973, but then changed its name to North Atlantic Refining and ultimately, today, is one of Korea National Oil Corporation producers of propane, butane, gasoline, diesel fuel, jet fuel, furnace oil, heavy fuel oil, and lube stock.
We have had some trouble getting information about the large (51 mm diameter) medals produced for the dedication. As best we know, there are bronze and silver medals, so Jerry's medal might be a gold plated silver or bronze one. Have it tested by a jeweler. If it is solid gold, Jerry has a very valuable medal, worth its weight in gold plus a premium which may reach about $100, depending on the severity of the scratch.
Here are some typical values as we understand them:
circulated: $5 US dollars approximate catalog value
fully uncirculated: $35
circulated: $50 US dollars approximate catalog value
fully uncirculated: $120