I’d keep the Squier in this case because, to me, it looks much better. It doesn’t hurt that the Fender would bring in more for resale either. And, I generally prefer a one pickup bass, so...the Squier.
However, what I’d also do (assuming an immediate sale wasn’t financially absolutely necessary) is I’d put the Jazz Bass Special in its case and "away" (like somewhere out of sight and without the easiest of access, like the back of a closet or under a bed or something) for at least a couple of months and see how I felt. If I didn’t miss it, well there ya go. Also, if I did miss it and pulled it back out, how did I feel after a while of having it back out? If I really enjoyed it and wanted to keep playing it, I’d repeat the process but with the other bass. If I still wanted to thin the herd and one of them didn’t seem essential after having provisionally put it away, I’d let that one go