Ok, let's try this again.
When I said years of your life, I really mean that. It may have been a year right now but you're going to take a very long time to heal emotionally from this, if you ever do. And that's what I'm concerned about.
In a divorce, the parties go to Court and divide their things up and move on. Except you don't get to do that. You're stuck in limbo, holding on to the notion there's a fair and easy process to finalize your relationship by the retrieval of certain items.
All of the "evidence" you have can and will be counter-offered as her defense that she doesn't have any of it, because 1) items were already returned to you or 2) you already took said items. It's a he said/she said argument.
You don't have to convince me of anything. I'm not the presiding Judge. I think if you thought you had a fighting chance to win, you'd already filed by now and gotten the closure you're seeking.
I'm trying to get you to move forward here, one way or another. Either file TODAY or don't. It's the only way to actually allow the healing process to begin. Do SOMETHING, TODAY.