I made the bottom of the box the same way from the back side of the record album cover - making it slightly smaller of course.
I was hoping to make some as gift boxes for a fun surprise, but I am not satisfied with the look of them. It's all about presentation, right? So, in the mean time, until I figure out a way to perfect this fun recycling craft idea, I will use the boxes I make to store some of my paper ephemera that seems to be abundant!!