It seems to me that you are asking if there is a developer that can give normal gamma and contrast to film that has been overexposed by two stops. You do NOT wish to do an N-2 development? I am not aware of a developer that can do this.(posted 8557 days ago)The Sterry method mentioned above is a means of reducing contrast without loss of film speed by bleaching the film prior to development. I have an article on it entitled "Latent Image Bleaching" on my site at http://unblinkingeye.com/Articles/LatentImageBleach/latent imagebleach.html. But I don't think it is the answer you are looking for.