I can find only the two aforementioned horsepower ratings, so I will have to make a slightly educated guess based on a calculation and you very generous hint. I understand the 6/24 had a displacement of 1405 cc, while the 6/30 had a displacement of 1550 cc. Based strictly on the proportioning of the displacements, and depending on whether one takes the 24 as correct, or the 30 (since generally rounding was involved) I get just under, or just over 27 hp.
Therefore, since Faun automobile production ended in 1927 or 1928, I'll try: Faun 6/27 PS Type K3 circa 1927 from Ansbach.