That's a great image - it will be hard to improve on the original! Do you have a link to the raw file?
(I edited my post a couple up from here - after seeing your explanation of the last edit.)
Here's a quick edit of the jpg image. I didn't crop or straighten because it looks pretty good as it was originally framed. I applied the Kodachrome effect I learned about a while ago. In Photoshop Mode -> Lab Adjustments -> Curves then simply narrow the a & b curves, keeping the center point in the same place. Some people will find the colors too bright, but I like them, and I like to hum the Paul's Simon's Kodachrome song in my mind as I do this. Then just a hair of sharpening and noise reduction in Lightroom.
How do I make that available for everyone.