Sanskrit mangalas in Indonesian texts

[czm1 at cornell.edu]

Friends on the list who work on Sanskrit in Indonesian texts:
        A student of music here has brought me a text about Gamelan music
based on a palm leaf manuscript in Indonesian which has an unmistakeably
Sanskritic beginning.  It reads: om awighnam astu nama siddham.  A few
lines later it reads:  "om sidhingastu nama ciwaya."  I know nothing about
Sanskrit in Indonesia.  avighnam astu is clear enough.  The question is:
what is this "Nama Siddham ?"  nama for namaH is clear, but what of siddham
? nama ciwaya suggests that dative with namaH is still possible, although
siddhiM astu suggests that case endings have in general lost some of their
distinctions.
        Any immediate reactions ?  Any reference works to turn to ?
Thanks,
C. Minkowski,  Cornell