The question remains even if the corrupted file is nearly repaired would the wallet be able to load the wallet.dat
There are dedicated tools like pywallet to extract private keys from corrupted wallets.
Unfortunately for the OP, they don't have a corrupted
wallet... they have a corrupted
ZIP file that contains a wallet.dat... that is a completely different kettle of fish, and PyWallet is of no use in this instance.
If the OP had simply renamed the wallet file... then there would be a possibility that PyWallet would be able to read (some) of it, assuming it could be "recovered" by the data recovery software... however, when you "zip" (aka compress) a file, that file no longer exists in it's original form and the data is changed until that file is then unzipped/decompressed.