[A. G. Maisey]

The foot of the atasan is the part of the atasan that projects below the body and accepts the tongues of the gandar, not all wrongkos have this foot.

The damage to the gandar is not at all unusual in Javanese wrongkos, a normal fix is as you described, just some newspaper or a couple of pieces of light cardboard fixed in place. Yes, a new gandar would be a distinct improvement, we use a tool called a segrek to hollow out the inside of the gandar. If we make it without a joint, the easy way to make one is from two pieces of wood, it should be a soft wood.

This appears to be a pretty fair sort of a blade, it will restore well, in my opinion it is definitely pre-WWII, probably second half 19th century.

This entire keris has the potential to be restored into a very nice keris.

Terminology.

the entire scabbard is called a wrongko (warangka) in Jawa.

the top cross part is the atasan (top piece) or gambar

the pendok & gandar you know