A Choquet type of an integral representation is found for a class of normalized positive operator valued (POV) measures on a Hilbert space. An arbitrary POV-measure within this class is thereby represented uniquely as an integral over projection valued (PV) measures. As an application, the case of a commutative system of covariance (representing a generalization of the imprimitivity theorem of Mackey) is discussed. The relevance of these results to the theory of quantum mechanical observables, admitting stochastic value spaces, is pointed out.