How to migrate from Oracle Forms 4.5?

Question

Oracle

Given: old base on oracle 7.3.4 + about 100 forms and reports v.4.5. It is required to migrate to an older version of oracle to increase performance.
Migration of the base is not difficult, but I want to avoid rewriting all the code and deep understanding of how the form algorithm should work. I see Forms & Reports for the first time and colleagues who know such a dusty technology are simply absent.
Where to begin? What software to use? Are there form converters or migration utilities, and how do I use them? Are APEX and old forms somehow compatible? What are the options?