Optical and IR data (black points) of oxygen-rich Galactic sources classified as post-AGB stars presented in Kamath et al. (2022), which we interpret as surrounded by silicate dust in the present investigation. The grey line line shows the ISO spectra from Sloan et al. (2003), when available. The red lines indicate the best-fit model obtained using the DUSTY code. The derived stellar and dust parameters from this study for each source are shown in the different panels.