For those who know the dark places to look for such things, there are a couple of versions of the OD&D booklets combined into a single letter-sized volume. I recently reacquired the particular version I like best, after having lost it in a hard drive crash quite a while ago. This one is formatted in the style of the B/X rulebooks, so I find it suits my tastes quite well. It was, however, lacking a snazzy cover. So, I took a bit of time and whipped one up. While I can't share the book itself here, I can offer my cover for those who want to use it.
The 12 MB PDF is >here<. Enjoy!