Manufactured by Lefstad sykelfabrikk of Trondheim before 1920 and in the 1950s.
Johan Peter Lefstad began importing bicycles from Austria in 1888, and established his firm in April 1892. The first motorcycles were Motosacoche machines which appeared around 1918 under the Nidaros brand. Motorcycle production resumed after WWII with mopeds, again using the the Nidaros marque, built from 1956–1958. Cycle and moped production ceased around the same time.
The firm continues to this day as a supplier of sports goods.
This motorcycle is all but identical to that in the Nidaros brochure from the 1910s: Motosacoche c.1914
Sources: nn.wikipedia.org/wiki/Lefstad_sykkelfabrikk, et al.