Both these units were used as demo pieces for my talks.
I have mounted a small (40mm) diameter fan to the rear panel so as to blow or draw some cooling air across the PA components as the PA will be mounted to one of the case side walls. There will be no external heat sink on the case. At 4W PEP out and class AB operation, the aluminium case wall should be sufficient to dissipate the heat of the PA with quite acceptable temperature rise inside the case.
I will post a picture of the finished transverter on here later this week ( optimistic?).