I would think it is West German or Austrian, East German tunics are very distinguishable.
Its twin is on ebay.de at present: 1 x alte Feuerwehr Uniform # | eBay
I'm also wondering what the ''F. Dufner'' means. Is it the name of the original owner or something else? The lowest front button is different from the rest, but it appears just as old and decayed.
The sleeves appear very wide for the tunic's chest size. Perhaps this is a custom tailored one and not made in a factory?
When I saw the Dufner patch first I thought it was the tailor that made the tunic but then, taking a closer look, I now think it is the former owner's name (the tailor would have added his address/phone number).
Looks like BRD Feuerwehr to me, though I don't know a lot about these uniforms. The indicators to me are the pointed epaulets, the black wool, four silver buttons (they should be solid backed), and the striped sleeve liners. Still, it's just a guess