© Published under licence by IOP Publishing Ltd. We consider the experimental data for difference, Δρ c (r), between the charge density distributions of the isotones 206 Pb - 205 Tl, deduced by analysis of elastic electron scattering measurements and corresponds to the shell model 3s 1/2 proton orbit. We investigate the effects of two-body short-range correlations. This is done by: (a) Determining the corresponding single particle potential (mean-field), employing a novel method, directly from the single particle proton density and its first and second derivatives. We also carried out least-square fits to parametrized single particle potentials; (b) Determining the short-range correlations effect by employing the Jastrow correlated many-body wave function to derive a correlation factor for the single particle density distribution. The 3s 1/2 wave functions of the determined potentials reproduce fairly well the experimental data within the quoted errors. The calculated charge density difference, Δρ c (r), obtained with the inclusion of the short-range correlation effect does not reproduce the experimental data.