To recover a wallet, you need either its wallet file or private key or mnemonic seed.

The FinderOuter, a bitcoin recovery tool.
[overview] Recover Bitcoin from any old storage format.

Base58check version prefix and encoded result examples
https://github.com/bitcoinbook/bitcoinbook/blob/develop/ch04_keys.adoc#base58check_versions

https://en.bitcoin.it/wiki/List_of_address_prefixes

If what you have starts with either 5, K, L, you have good backup to go but you don't have it.