One my favorite OSR games is The Hero's Journey by James Spahn. James takes Swords & Wizardy White Box and mold it into a Middle-Earth flavored gem of a game. Well, he was quite satisfied with the result and so he has reworked it. You can read about his reasoning on his blog here and some of the changes and some excerpts here.
And it just went up on Kickstarter today. As I write this it's less than $200 away from it's $5000 goal. Have a look if you're interested.