I don't know how old it is - my guess based on the font is late 1800s-early 1900s. The lettering may be a match for what is on this one. A Danish seed bag seal.
Inscription on reverse in full is likely to be STATSFRØKONTROLLERET. Statsfrøkontrolleret means - Stat = Goverment Frø = Seed Kontrolleret = inspected and means that the seeds are guaranteed to be disease free by the government (with thanks to Danzigman for translation).