Also, in the forums here, there is a link to an outstanding fictional United repaint by Bigjuicyspider. If you read his posts leading up to the completion of the project, I think you get the idea that repainting the 377 is a daunting task.
The link to that file is no longer valid and I removed it now, thanks to the 1000's of Viagra ads I started getting in my inbox after hosting it at that site. I'm far too critical of it to put it out for wide distribution, but I guess if somebody specifically wanted it, I could put it up somewhere. Only public repaint I've ever done, and it was tougher than I thought to make it satisfactory, but thanks for the complement.
Also, as Jacques says, there are dozens of repaints available at Avsim, Flightsim, Aussie, etc, but I don't know how many of them are done at high res.
My One Thousandth post. Have I really had that much to say? Anyway, don't I get promoted to A2A Deck Swab or something now?