FEHO, or fully "Fehodor", was a minor radio manufacturer from Eastern Germany. Informations about their speakers are somewhat scattered. So you better state size and type/number of your FEHO fullrange driver, so that I might look for them in german loudspeaker forums. Some pictures would help a lot too of course.
If you could precise, what kind of information you are looking for, this would be helpful too. Is it T/S-Parameters, historic context, plans or what else? Sampling "ALL information" certainly would be more time consuming than I am prepared to do