The Never-ending Spool

I have been culling pairs without enough contrast and plan to recycle them back into the project. However, I already have 900 pairs. I had started to sort them by the color of the darkest spool, but while I was sleeping, Buddy unsorted them. He also dropped his possum toy on top of the pile so I wouldn't know who was to blame. (Sometimes I will find possum at the food dish, sometimes he comes to the bedroom, then back to the sewing room).

Here are the four-patches I have made so far. As a reminder, the key challenge to this quilt is that it is a charm quilt, where each spool is made from a different fabric. Unfortunately, as I was sorting pairs, I found a duplicate fabric!!!! This means my strategy for removing duplicates was not foolproof and my only remedy is to pack this project away and never think of it again.