It does look used and possibly older than than a few weeks. The handle has lovely grain and I like the colour too. What I meant (and I mean this to be constructive, not negative) is that you stopped working on it a bit early. The false edge on the top for example, looks ‘squashed out’ where it rises above the spine then drops back in line. The line doesn’t look straight or deliberately curved - like you forgot to grind it back straight. Could just be the photo though but you did mention odd curves - I suspect this is one? Also to my eye the file teeth should be visible in a whole area or not at all, not just a few random spots.
Personally I think your sheath is very decent for a first. What I really like though is the bolster. That groove is a very nice touch.
I found this book quite useful from a beginner sheath making perspective (sorry, I don’t see it on Amazon.nl). I probably wouldn’t have bought the second volume if I’d been able to look through it in a shop. Hope it can help you too.