Comparison of an observation of just HD 72106A (black, 2007 March 5), a combined observation of HD 72106A and B (dark grey/blue, 2006 January 11), and the corresponding reconstructed spectrum of HD 72106A (light grey/green) obtained using the procedure described in Section 4. A good match of the reconstructed spectrum to the observation of the primary can be seen in the core (upper left-hand panel) and wings (upper right-hand panel) of Hβ, as well as in weakly variable metallic lines (lower panel).