The four T*-type solid solutions Nd1.2Sr0.8-xRExCuO4-δ (RE = Y, Ho, Er, Yb) were synthesized and studied in terms of homogeneity range, structural study (neutron powder diffraction) and electrical conductivity. The homogeneity ranges have a small extent around the value x = 0.4. The main crystal chemical properties are as follows: a full ordering of Sr2+ and Y3+ (Ho, Er, Yb) in the Rocksalt (RS) and Calcium Fluoride (CF) slabs, respectively, Nd3+ distributed on both slabs; an overall oxygen deficiency δ in the range 0.15-0.18; oxygen vacancies distributed in the CF slabs (12%) and the equatorial `CuO2' planes; interstitial oxygen in the RS slabs (# Nd0.6Sr0.4O1.04). Electrical resistivity measurements (RT - 4 K) of samples annealed under pO(2) up to 1800 bars point to a `dirty metal' behavior up to 25 K (Y, Ho) and 70 K (Er), followed by a semiconductive regime at lower temperature. The big difficulty to get a superconductive transition in these phases and more generally in the T*-type cuprates is strongly dependent on the nature and the amount of small lanthanoidic cation in the CF slabs.