Just search the coin and go to the market tab you will see all listed exchanges for that coin.
Or at some point, the OP can't find those coins on those coin checker websites
(CMC and Coingecko), then probably that coin was delisted a long time ago or been inactive in development for years. In that case, deep research via OP's preferred search engine is necessary.
OP, sort your problem out by not looking on the active exchanges in 2014 but rather search directly on that specific coin.
I have dozens of coins on old hardware wallets or USB sticks where the blockchain is dead for a long time and they aren't even to be found on coinmarketcap anymore. If they are not on coinmarketcap, there is basically no chance you will find it anywhere else. Even if you do there won't be any market for them.