Old School: the origins of Castle Caldwell

An obscure little drawing in Issue #54 of the diplomacy zine Arakkis in 1976. If the layout seems vaguely familiar, it is because that is the same basic castle layout as the D&D adventure module Castle Caldwell.
Beyond the drawbridge a gatehouse with rooms left and right, then a hallway with inner and outer rooms, and round towers accessible from the halway at each corner. And a central bailey accessed by a door at opposite ends and three rooms on the east and west walls accessible only from the inner Bailey.

The D&D adventure module was published in 1985.

Perhaps not as faithful to the original drawing, but what could have been a multi-floor castle clear-out...