Its not for me to judge, but you should probably state on the game's page, that you reused some code from previous project
Here's what it says in the rule:
- While you can use pre-existing code or assets, refrain from writing code or creating assets specifically for this jam in advance unless you are releasing an asset pack for everyone to use. Remember that the point of the game jam is for you to create your entire project within the 72 hours period.
- Feel free to utilize pre-made, publicly available, or purchased assets, as long as you have a license for them and proper credit is given as necessary.
So I'd say mentioning it on page probably is something u should do, yeah.