Photographs can always be misleading, but this doesn't look like a layered metal construction to me. It is a keris form which is commonly made as a repro known as naga sasra. It does indeed appear old, but this is very easy to accomplish in a relatively short period of time. If you want to clean it up to see if there is any pattern weilding try soaking it in pineapple juice for about a week, brushing it down a couple times a day with a hard toothbrush. There may be a surprise under there, but i doubt it. I have seen these repros in all levels of quality, some qualify as "true" modern keris while others are cheaply and non-traditionally made cast iron.
The hilt on the other hand looks like the real deal and certainly has more value than the blade.
