The Collaborative International Dictionary of English v.0.48:

Salvor \Sal"vor\, n. [See Salvation, Save] (Law)
   One who assists in saving a ship or goods at sea, without
   being under special obligation to do so. --Wheaton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

salvor
    n 1: someone who salvages [syn: salvager, salvor]