Alan,
I couldn't find the name Nenggala in Raffles' book.
Regarding Tumpuling, there is a similar spear in Radya Pustaka Museum, in it's description it is called Cempuling. Wiktionary says, Cempuling is a variation of Tempuling (
https://id.wiktionary.org/wiki/cempuling), and Tempuling is given as tombak pendek untuk menangkap ikan besar, short spear for catching big fish.