Forget the idea of "three pieces", just focus on time to make a forging from which a keris can be carved.
The bulk of time to make a keris with a plain mlumah pamor is in the carving.
This keris was made 100% in Australia, at Wentworthville, I used a coke forge, I worked completely alone, no striker, no power hammer.
It was carved completely with manual tools, no electric tools.
It is not a mlumah pamor, I made a mlumah pamor then turned it side on so the central portion of the blade face is adeg, so there is a bit more forge time in it than if I had left it as a wos wutah.
Total working time was 16 days, at 6 and 8 hour days, say, +/- 110 to 120 manhours.
I do not recall exactly how long the forge time took, but it was probably about 3 days, give or take a bit. It is a normal, full size keris.
For comparison, this one:-
was forged in Solo, working with two strikers, it took 3 days of forge work with two strikers, so 9 mandays. It was forged on charcoal, they were not 8 hour days, more like 6 hour days, or less. It is half size keris, and it is a manipulated (twisted) pamor.
I carved it in Australia, again, only manual tools, no electric tools, total working time was +/- 40 carving days + 9 mandays forging, total 49 mandays.