How can I create this?

I believe we are clearly going..

off topic

I didn’t “kept” doing anything, I only asked once.
Because HE asked for EXACT shape, which of course needs EXACT dimensions and sections.
Still nobody arguing with that specific statement, but everyone loves to be offtopic just for the sake of it, I guess.

I’m not sure if you are trying to be ironical, but since I subscribed to this forum, I most likely try to help someone else rather than asking for help.
To be exact, I doublechecked and I asked for help only two times in ten years and I did it like a behaviorally normal adult should, so that you don’t need to look to my profile to help (also.. considering that I can access and use multiple Sketchup versions on multiple PCs, multiple graphic cards and multiple operating systems).

That’s how I asked for help here:

How to "reset" extension warehouse account to exclude old pc's no more in existence?

Need help identifying a Plugin used in a Tatlin Sofa You Tube video - #11 by panixia

so..

¯_(ツ)_/¯

edit: I missed this point:

Well, you can doubt all day long, but I do not design sketches to try to explain, I do not download, open and analize someone else file just for the sake of criticize it and state that “I’m an expert” (which I never said, btw).

I was clearly trying to help and I also wanted to model that piece (the fading grooves are actually easy for me, even exactly proportioned.. provided taht one adds proper references and dimensions).

Of course I’m not willing to help anyone anymore, being that if someone point outs problems that needs to be addressed, then becomes “the villain”
So that even original poster feel authorized to be unecesseraly rude and reply like this to someone willing to help for free. That’s fine, I guess.

How can I create this? - #17 by Josef1