Grace, I agree you should keep the mementos. If you're not sure, hang on to them a little longer. Just finding an "out of sight" location can be difficult, and I realize that.
I sent a few things to my parents house, and they are kind enough to hold on to them. My wedding album, my dress, a few photos. Smaller mementos are in a box that I have sealed, labeled, and set aside in a closet where they won't be damaged but I also don't have to see them. Do you have a dear friend or family member who would understand your need to not see them? The trouble then is liability - if anything happens to them while at another's home you can't really be angry.
TBH, I never offered my STBXW any of the mementos. She left without taking any or asking and so I consider myself the keeper of the good memories. I'm pretty angry at her currently for what she's done, but I insist on keeping the good memories from years ago. So I tie them up neatly, set them on a shelf, and refuse to have my current emotions tarnish them.
