Hi Detlef,
Nice job with cleaning the blade.
It looks so much better without the active rust and pitting. It also shows a nice lamination!
I have no clue about the surface of the blade near the tip.
The missing gold inlay (partly or totally) on several old sikins is more common.
It once looked like this in its best days....
Always keep in mind that they were all warriors, so war related damages and missing parts can occur
Kind regards,
Maurice