Gotthold Haffner Gmbh + Co. KG Maschinenfabrik based in Ötisheim, Germany filed for bankruptcy in 2011 and ceased trading in 2012. The company made power tools for the trades, but disappeared with hardly a trace. Some of the tools still pop up from time to time on the German eBay, but they tend to be industrial machines.
I doubt you will find much about the Haffner tools online. I looked for the manual of a different Haffner power tool a few years ago for someone else and didn't have any success. I live less than two hours from Ötisheim and was tempted to drive there to see if there were any shops that might have old stock or information. One of my friends, who used to be in the tool salvage business told me not to bother. When Haffner folded, everything left in the buildings was sold for scrap or taken to the recycling center.