on second thought, your metoposaurs fit the bill, lungs=scales of course, but these look leathery as if scales were secondarily lost, or under the skin.
As with dinosaurs, bald or scaly forms of even transitional creatures is possible, even likely. Solnhofen was apparently arid, so possibly compsognathus was scaley, and as such, mastodonsaurus could have had leathery skin, seeing as tropical climates tend to favor non-overlapping scales or plain none at all, to avoid infection.
Russian capitosaurs is known jnly by skulls and some pieces of postcrania. About skin of capitosaurs - see, for example, original description of Paracyclotosaurus by DMS Watson: some little scales was found, but not overlapped. Also exists article of F. WITZMANN (2006) about temnospodyl scalation.