RE: McCormicks Iron glue
M in a circle is Maryland Glass Works and has been in use since 1916. So bottle dates post 1916.
McCormick's is the same as the spice company and they made a lot of different items including Iron Glue. Motto was "Sticks everything but the buyer".
It was made from about 1900 till 1920 or so. So the makers mark and the product match.