German Antique Buffet

I have from my family estate, 3 pieces of furniture from Germany. I am unable to find any information as to the maker or value of these pieces. This first one I am inquiring about is a Buffet cabinet. I do know these pieces were shipped here from Heidelberg Germany approx. 20 years ago. They belonged to my grandparents in Heidelberg since the late 1940's I am told. All 3 pieces appear to be a set. There is this Buffet, a Sideboard, and a Dining Table with 6 chairs. I remember these pieces when I visited as a child in the 70's and 80's. The only real distinquishing mark I have found is on the back of some drawers in the Sideboard. I am including a picture of that Mark. Also, the pieces have writing on the back of them (some not distinquishable) in an un-stained area.

Again, these pictures are from the Buffet, and the possible Makers Mark is from the Sideboard which I will post about later.

I am looking for the maker, any history and possible value of this piece. Thanks for any help provided.