Possibly no external difference?
In the early 1990s, on the RPSI May Tour, when the Society used to hire Cravens from IE, on several occasions we simply removed two or three seating bays the night before in the Valeting Plant, and installed a counter and bar. At end of tour we put them back the way they were.
Point being, things like this could be done for any period, however short, and zero external changes.
I wonder if these other conversions were similar. I'm 90% certain that no other Craven (apart from 1508/9) ever had external alterations like blocked up windows.