First of all,, never touch the finish on a piece of that age !! A light wax is fine but never remove the original patina !! If you do all you have left is a piece of used furniture !! Better pics will help and if possible flip them upright !! Need good pics of both items and as was said the dovetail joints are important to determining age as well as the hardware,,pic of the back ect !! You call it a secretaire bookcase but I see no writing surface !! Show all please !! The details will help !!