Many thanks to both of you, it's close to what I read on other forum.
So the valve guide is really in perfect shape, just a few scoring on the exhaust valve stem (I already sand/polished it - this remove protruding material, even if it wont fill the missing material...).
Now waiting valve lapping tool (can be long...) and I find someone that can give me a little bit of lapping paste/compound.
No major progress these days... but lot of other things to do - and no hurry - this is is side project :wink: