is there any way to determine if an numpy array is record/structure array?

Neither of those are record arrays. Per the docs:

>>> x = np.array([(1.0, 2), (3.0, 4)], dtype=[('x', float), ('y', int)])
>>> y = x.view(np.recarray)
>>> type(x), type(y)
(<type 'numpy.ndarray'>, <class 'numpy.core.records.recarray'>)

ndarray.view creates a new reference to the same memory, and as you call it also names the fields. There isn't a fundamental type difference between your c0 and c, they're both ndarrays.