I'm far from an expert, but from hanging around here and Gun Broker for a few years I would tend to agree with Jack Flash - and lean towards the high end of his guesstimate.
Factory refinishes, especially if done early in the gun's life, don't seem to kill collector value the way aftermarket finishes do, and a nice set of cokes will fetch $600 all by themselves.
If the box, tools, and paperwork are included that adds a couple of hundred clams to the value.
Add a hundred bucks premium for the 4" barrel (they seem to be about the most desirable) and you're at or near a grand in value just for all the "extras".
So, all that being said, somewhere close to $2000 for a complete "flawless" 5-screw pre-model number 44 magnum package doesn't seem outrageous to me at all.
Particularly if it is of the '56-'57 vintage for the cokes to be period correct.