Do you mean older version of "Bitcoin Core" (which called as "Bitcoin-Qt" or "Bitcoin) when you say "Pre-Core"? If yes, you could just download the older version and generate a new wallet file using it. You can use these links to obtain the older version,

• https://bitcoincore.org/bin/ for version 0.8.6 and newer.
• https://satoshi.nakamotoinstitute.org/code/ for version 0.1.3. and older