Big Hella chrome fanfare horns

A set of Hella chrome fanfare horns in used condition. I tested them with a 12V battery charger and one was working good and one was working a bit only. Maybe you can fix it just with more power from a battery, or after cleaning the contacts outside and/or inside. They are without dents which is very rare. The top cover chrome has chrome pimple, the grill chrome is good as far as I can see but I guess that behind the oily motor dirty is good chrome. Hella made these in 9,5 cm diameter and 11,5 cm diameter. These are the 11,5 cm diameter “big” Hella fanfare horns. One horn is high and one low tone. They are 2350g heavy and made in Germany.