Fight Over A Renoir

This is a complicated one. Ready? Here we go:
    A woman buys a painting at a flea market for $7. She assumes it's a fake.
    After two years in storage, she wonders whether the painting is authentic, and decides to have it appraised.
    Turns out the painting is documented as a Renoir.

Still with me?
    The woman puts the Renoir up for auction. It's expected to fetch in the neighborhood of $75,000. (It's a small piece - 5 1/2" x 9".) Every flea market enthusiast is green with envy.
    Only a few days before the auction, the painting is pulled. Turns out:
    A Washington Post reporter discovers it -- or a painting very similar to it -- was stolen from the Baltimore Museum of Art in 1951.
    But an insurance company already paid the Baltimore museum for the stolen painting back in 1951. (It was valued then at $2500.)
    The original owner had only loaned the painting for the exhibit back in 1951 -- though it's believed she planned to give it a permanent spot at the museum. (She'd donated many other works.)

    So who owns the painting? 

The original owner...or the museum...or the insurance company?

 Or is it the lady who purchased it at a flea market, and inadvertently brought all this to light?

    That's the big fight right now.

  The flea market painting, documented as "Paysage Bords de Seine," or "On the Banks of the River Seine" by Pierre-Auguste Renoir. Photo from the Washington Times link.