On Instagram check out @vinylboxes for a flipping style box. He charged me $50 for two 40 record capacity boxes. They're sheet metal and he makes them himself. He also makes a small size that holds 20.
I have the (original) Expedit shelf (now Kallax) and the particular crates are a hair too big. I can force it in to fit, but being sheet metal it will scratch the shelf sliding the crate in/out. So instead of putting the crate in the individual cube I put it on top to hold my most frequently played records.