I imported the private keys onto blockchain.info.
The balance is there in my wallet but block explorers are showing me as having fuck all balance.
I do not understand this.
Its a common misunderstanding.
Lets say that your wallet contain 1 private key, we will call it A, there is 0.01 BTC of input to A:
Wallet balance = A = 0.01 BTC
If you check the balance of the public address associated with private key A, then will the block explore show 0.01 BTC.
So far so good, very easy to understand.
Now you import private key B and C into your wallet, B = 1 BTC and C = 2 BTC.
The wallet now control 3 private keys: A,B and C.
Wallet balance = A + B + C = 0.01 + 1 + 2 = 3.01 BTC
If you check the balance of the public address associated with private key A, then will the block explore
still show 0.01 BTC.
Obviously if you check the public key associated with B it will show 1 BTC.
This can cause a lot of confusion for the average user.
Now if you transfer the whole ballance to a completely new and fresh wallet, lets call it D
Wallet balance (new wallet) = D = 3.01 BTC
The next thing to consider is change addresses, which is used when not moving the entire balance (in realality it is "inputs" and not ballance, but no need to go into that).
This just adds a new level of confusion.
Bottom line, average user should use a reliable wallet, and only concern about the balance.
If you don't want to be an average user, then study how the bitcoin transaction works and how the specific wallet handles them.