What do you call someone who finds everything?

There's this film, a classic, starring Steve McQueen and Richard Attenborough, set during the second World War at an Air Force Prisoner of War camp in Germany. The film, if you haven't guessed by now, is called The Great Escape, based on real-life events that happened in Stalag Luft III, Sagan, once a German town, 100 miles south-east of Berlin.

In the film there is a Flight Lieutenant pilot called Robert Hendley, an American in the RAF, whose nickname is "the scrounger"

who finds what the others need, from a camera to clothes and identity cards

Interestingly, the actor who portrayed this role, the gorgeous-looking James Garner, had been a soldier in the Korean war and he too had been a scrounger during that time. Unfortunately, today the term has very negative connotations especially in BrEng where it is synonymous with moocher, sponger and a freeloader but according to War Slang. American Fighting Words and Phrases Since the Civil War by Paul Dickson, its meaning was slightly more noble.

Scrounge. To appropriate; to misappropriate. In Behind the Barrage, published shortly after the war, British writer G. Goodchild discusses the term:

In the category of "odd jobs" came "scrounging." "Scrounging" is eloquent armyese; it covers pilfering, commandeering, "pinching," and many other familiar terms. You may scrounge for rations, kit, pay, or leave. Signalers are experts at it, and they usually scrounge for wire. Scrounging for wire is legitimized by the War Office, and called by the gentler name of "salving."

and further on

scrounger. One adept at acquiring food and other goods.

Oxford Dictionaries says scrounger in AmEng is

A cleverly resourceful person who finds and procures items for a specific purpose

So, it kinda fits if the character is American or is given the nickname of Hendly; however, the author would have to give a brief justification for this name.

Trouvaille: it means a lucky find or discovery

If they're the first to find things:

pathfinder - a person or group that is the first to do something and that makes it possible for others to do the same thing

If their ability to find things is divine or they have foresight, they might be a:

diviner - someone who claims to discover hidden knowledge with the aid of supernatural powers

or a

seer - a person with unusual powers of foresight

If they are always in search of finding things, they may be a:

fortune-hunter - a person who seeks to secure a fortune

If they just have good luck, they may have a lot of:

serendipity - luck that takes the form of finding valuable or pleasant things that are not looked for