A useful distinction
A historical menu can reveal what one establishment chose to advertise at a particular time. It does not independently establish how every dish was prepared or how representative that restaurant was. The object’s context gives its wording meaning.
Put it into practice
Record the collection, date, location and any uncertainty supplied by the museum. Keep prices and historical descriptions tied to that period. Do not present them as current offers or reconstruct a recipe solely from a dish name printed on an old menu.