I think Bruno Arnold (1884-1933) is probably on the right track, but your pics have what looks more like a ‘studio mark’. So it may depend on how old the pictures are because his son Hermann followed in his father’s footsteps and continued to run the studio after 1933.
Bruno Arnold (1884-1933)
Arnold originally wanted to become a gardener, but his health constitution meant that he learned the photography trade in Leipzig. In 1911 he passed his master craftsman examination in Kempten (Allgäu), moved to Füssen and opened a studio at Luitpoldstraße 8. In 1912 he married the daughter of the brewery owner Margareta Deuringer from Kempten. In 1915 his son Hermann was born, who after the early death of his father in 1933, continued the studio until 1977.
In addition to earning a living as a local photographer, Bruno Arnold began to take intensive photos of his homeland in the Allgäu. In this way, a large number of recordings were made with high artistic standards, some of which were only possible after an arduous ascent in the mountains. His photos of Füssen and Hohenschwangau are of particular interest [Note that this is from a German source and the 'interest' is probably small outside Germany] - only a few decades after the completion of Neuschwanstein Castle, he documented the scree slopes of the construction work or the change in rural architecture to more urban forms of construction.
Definite shortage of his pictures online, but here’s one of them: