Only addresses that have had transactions will show in walletexplorer, so that's not going to work for by the sounds of it...
He provided all the addresses for the coins.
If address list is lost AND coin is not funded..your not going to find public key unless you reach out to previous owners
If coin is loaded..then enter firstbits on walletexplorer
If you peel holo...you will find the private key underneath.
I fixed one part for you... https://bitcointalksearch.org/topic/--5298712.)
I hope you can get it from the original seller, as smoothie will likely ignore your request unless you were the original purchaser.