Kling Chest of Drawers

This is a chest of drawers that I got. It is made by the Kling manufacturing company. The back stamp shows that it is from the 400 series. I bought this chest with a bedroom suite. It was originally a bed, dresser and mirror, 2 nightstands, and chest of drawers; but I did not get the nightstands. The set I did get matches, and according to the back of the dresser, it was made in 1939. After getting this chest of drawers, I realized that one shelf had hinges on the side of it and I found a latch on it. I knew that it had the pigeon holes, but I also found out that it is apparently a secretary. I was wondering if anybody knows any more about this piece? (i.e. were many made like this and how much it might be worth? I have been searching online for several hours, and though I found a few chest of drawers that looked almost identical, none of them had the secretary built into it.) Any help would be much appreciated. Thank you.