Oh dear~ that's a shame 😞
Not sure how you could proceed since you stated you don't know when it happened or which guest it could have been.. Also, it could be one person who caused damage and another moved or took the record.
Did you look in other rooms for the record ? Maybe someone was reading the cover someplace else.
You'll need to scale down items you leave out so there's less chance of personal things being tampered with. Lock up anything of personal or monetary value. You can lock a cupboard or closet.
Sorry this happened !