There is no publicly documented information on a 12-gauge double-barrel shotgun bearing the exact markings “Marixa Eibar Made in Spain Volunteer Blumenfeld Co Menphis.”
This suggests it may be:
For definitive identification, consult specialized forums (e.g., GunBoards, ShotgunWorld), a qualified appraiser, or the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) tracing center.