~snip~
My apologies; I tested with an address under the wrong header. Any idea whether the seed is in a standard format that either the BIP39/BIP32 javascript tool, or Electrum, will take?
as bL4nkcode said electrum accepts BIP39 seeds which seems blockchain.info is also using. if you are looking for additional tools you can use this one:
https://github.com/iancoleman/bip39 which is in Javascript. there is also an online version here:
https://iancoleman.github.io/bip39/ but it is best if you clone the repo and use it offline.