Normalised spectrum of KKs58-NSC (top) and KK197-NSC (bottom) fitted with PPXF and the scaled-solar MILES models. The input spectrum of the NSC is shown in black and the best-fitting combination of MILES SSP models is shown in red. The blue points indicate the residual, shifted to 0.5 for visibility. Masked regions with strong sky residual lines appear as grey-shaded. Right panels: available grid of MILES SSP models in age and metallicity, colour-coded by their weight in the best-fit. The pink crosses mark the position of the weighted mean ages and metallicities. These are not corresponding to our final measurements from MC fitting listed in Table 2.