Last post by imporntant:
I think the build corresponding with your mentioned blog post is "Opera Mini Android 4.2.13670 int (2009 02 02)", because of the blog post and build date similarity. I found it here.
Not every released OM build has a blog post. Here is another 4.2 for Android: Opera Mini Android 4.2.14427 int (2009-06-04).
Not every released OM build has a blog post. Here is another 4.2 for Android: Opera Mini Android 4.2.14427 int (2009-06-04).