LMD has digitized many public domain Sinhala classics. They offer a paid, high-quality Unicode PDF of the Jataka Mani Manjusha with a modern introduction.
A genuine typically includes 34 to 40 chapters (depending on the recension). The most famous stories included are: jataka mani manjusha pdf
For those looking to study pure Parashari astrology , this is considered an "old-school" authority that doesn't dilute the classical rules. LMD has digitized many public domain Sinhala classics