In my knowledge: the answer is no.
Before starting the conception of the USM Tweaker, a long-term and weary work, I was interested on this subject.
So I contacted the original dev teams years ago. The answer was very clear: not only they don’t have the code, but they also don’t know who to contact.
But on top of that the original studio has been taken over by
another company which itself has been taken over by another one
years later. In a few words, the original source code is sleeping
in a safe somewhere, if it has not been lost…
Last sad thing: it is not in the habits of the video games studio
to release old code nowadays: the trends of the retrogaming has
shown that they can still make a lot of money with old stuff.
And to finish, there is legal issues: if a game use third-parties
technologies, the original studio has paid royalties for it, and they
would be prone to legal prosecution by releasing it.