Well, I'll say it since no one else has. Each one of you may have a problem. If asked and truthfully answered, many (most?) would have 30+ molds with some stating "I'm not sure". How many do you really use? Doesn't matter does it! Whether it's a sickness, a hobby, a way of life, etc. etc. etc. and I love it!
I've made a habit of storing mine back in their respective boxes. Originally I wrapped a rag around them but found that even though my shop is dry, South Carolina doesn't care. I still put them back in their boxes, now I just wrap them in VCI paper and put them in plastic bags first. The rust spots disappeared and I look for more space for molds.
I really like the individual sealed plastic boxes. I already do that for colors for PC (about 10 different Rubbermaid boxes).