Since nobody seemed to upload any resources here, I took a little bit of my time finding for some, and stumbled upon this site.
Rabaul Creole German (Unserdeutsch) Project by the University of Augsburg (in English) (auf Deutsch)
It has some published works regarding the language, as well as audio recordings of the spoken language and photos of Vunapope, both from the older and more recent times.
The project is still under active
construction, so it may not be complete enough for you.
وَمِنْ آيَاتِهِ خَلْقُ السَّمَاوَاتِ وَالْأَرْضِ وَاخْتِلَافُ أَلْسِنَتِكُمْ وَأَلْوَانِكُمْ ۚ إِنَّ فِي ذَٰلِكَ لَآيَاتٍ لِلْعَالِمِينَ
"And of His signs is the creation of the heavens and the earth and the diversity of your languages and your colors. Indeed in that are signs for those of knowledge." (Ar-Rum: 22)
Jika saya salah, mohon diperbaiki. If I make some mistake(s), please correct me.
Forever indebted to Robert A. Blust for his contributions to Austronesian linguistics