A while back a site appeared offering replacement cases for pre-recorded MiniDiscs: https://minidisc.me/   They were offering them in a variety of colours but they never actually seemed to have anything in stock, at least not when I looked.   Anyway, Retro Style Media in the UK, who also sell blanks and the smaller jewel cases for MiniDiscs, have now got the larger cases in stock: Full Size MiniDisc Case with a Black Inner Tray   They're not cheap but might be worth