Hello Mcassella
These tin ice packs were very popular here in Canada and south of us in the US during the 50's and 60's. Millions of them were made but few remain. They either rusted out because they were always in a wet environment or they got tossed out when the newer plastic covered ones came along.
Sorry to be the bearer of disappointing news but your tin is worth very little. As with most advertising collectibles there has to be some basic things to give it value. Subject matter, condition, rarity and someone who wants to collect it all factor in.
Here's 3 ice packs that I have in my collection. They are in good condition and have interesting subjects but I paid under $20 for each of them. I like them. Many collectors wouldn't be bothered with them but that's okay. Collect what you like and pay what you feel is right for you and you will never go wrong.
Vlad