OK. I give up.
4d Prisoner's here? (5) O-L--
12a Fitting light green opening in middle of lounge? (7) --A-ING; and
24a Traveller swindled pair from Rome clothes company (7) D-D-C-I.
Thanks you eleanormcn - I can now sleep easy having learned a new word (oflag) and I can see the logic of glazing though I think the overall clue a bit suspect