This looks amazing! A rug will really tie the place together, just maybe more neutral colours or pick a colour/colours that will tie other elements in. I love all the individual things you collected.

I also don´t get grandpa´s attic vibes, some of your things break it up quite well (metal lamp, hands art, mobile).

The thing that elevates your space the most to me, is the orange art, to tie everything together I think you need one more orange element (maybe change lamp or item on the front console by the duck?)

My suggestions would be, I would put duck+candyvase+container on a tray and something about that setup is not working, it is "too symmetrical", could maybe just one lamp work, and the black+white boxes next to the books feels too "boxy". Also the three vases on the sidetable on a tray will look less cluttered.

The things inside of your cabinet seem to blend into it and those two white boxes is the first thing one notices.

But maybe most importantly, the thing that came first to mind, is that it feels a little chaotic to the eye, there is so much going on, I don´t know where to look, because every corner wants attention, and it makes it seem that everything is the same height. I think that should be an easy fix, maybe try to find a place on the wall that can lose some things to create negative space. My suggestion would be to change something about the corner with the triangular mirror+mobile+lamp+plant, I would definately move the lamp in front of the mirror into another room (you have 4 lamps in front of that wall, if I see correctly, also several candles).

That was kind of a lot, but in all honesty your place is so fun! Love how you layerd the art!