... Objective prism (OP) spectroscopic plates collected with Schmidt Telescopes are a heritage of the pre-electronic Astronomy which may still contain useful data for statistical researches, and precious information on unrecorded peculiar events as well. ... Within a National Project aiming the scientific use of old astronomical plates, we have analysed a set of OP plates obtained during 1969-1975 to follow the spectral evolution of the symbiotic nova HBV 475 (also named V1329 Cyg). ... 2003). ...