Good buy Pak ganjawulung. Very nice deadly little piece.
This is indeed from southern sumatra, Palembang keris. The sharp bend curve is unusual but not uncommon. Here we can see the fusion between mid Javanese and typical sumatran forging techniques. It is typical for sumatran keris to be quite thick as it is for practical use.
The ivory hilt doesn't seems right (my personal opinion). You can have it change. To me this ivory looks like for badek or sewah..
I hope you can post 'as it is' picture and not edited. I would love to appreaciate more of this cute fellow.