I think you got a point there, Detlef.
Because of the norm, I've seen most bugis keris without its etching and on certain point, it is nice to see it like that.
But if the pamor is traceable and outstanding, etching seems to be just fine, as in case of your palembang gonjo iras blade...
Meanwhile in this case, perhaps do nothing is best
It is a keris in a good state, but do it really have some ages? It doesn't look new, nor did it looks too old as well...