A new one on me (and no entry in the VAG). It appears that FABARM (best known for good value shotguns), made an air rifle (including perhaps for other brands, though that reference in the link below may be to shot guns) in the 1950s. A very conventional underlever along pre-WW2 Diana lines.

http://www.fabarm.com/web_eng/storia.asp

Anyone seen one, or know more?