Author here. Sadly, not without a current toolchain, plus all the custom changes for Mac OS 9 on top of NSPR and other pieces. CodeWarrior is a solid compiler but the classic Mac OS versions definitely show their age compared to modern gcc and clang.
Regardless, thank you for all of your work and contributions. Keeping those old PPC devices alive did more for the environment than I think you'll ever be able to quantify. Not to mention, I had a lot of fun with old PowerBooks and iMacs surfing the web.