Hello,
I have only 2 knive and one Kabeala, all are recent (between 1945 and 1990) and all in Bondokodi style. But they are never cut-out on the backside of scabbard mouth.
But I noticed that this area is very frequently broken on the scabbards of badik, mandau, kalasan etc... (at least on those that I own).
The cut-out can be made to limit the risks of breakage in this apparently fragile zone of the sheaths.
