Posterior probability distribution of the four key parameters of the model: the Hubble constant, the stellar population synthesis mismatch parameter, the average log M_DM, 5, and the average γ_DM. Purple filled contours correspond to the fit to the sample of 100 time-delay lenses, with no extra information. Red lines show the posterior probability obtained by using prior information on the model parameters from the sample of 1000 strong lenses simulated in Paper I. Contour levels correspond to 68% and 95% enclosed probability regions. Dashed lines indicate the true values of the parameters, which are defined by fitting the model directly to the distribution of log M_DM, 5, γ_DM, and log α_sps of the mock sample.