Oxygen-17 NMR measurements were used to probe the electronic structure in two transition metal oxides : (La0.6Sr0.4)(Co0.8Cu0.2)O-y and (La0.5Ba0.5)(Co0.7Cu0.3)O-y. We find that the shift of the resonance in both materials can be deconvoluted into a temperature independent Knight shift and a temperature dependent Curie-Weiss shift, suggesting that localized and delocalized electrons exist simultaneously at high temperature. We discuss these observations in light of the complex local structure found within these materials.