Origin and use of "in and among itself"

Solution 1:

The usual expression is In and of itself, used for emphasis, so the expression in your question seems unusual.

Could it be a deliberate mistake? We need to know the context.

For example, it seems ungrammatical to say among itself since 'among' implies more than one member of a group -- but does 'itself' refer to a group?

Context would help ....

Solution 2:

Google search results for this bring up a lot of instances where it seems that it is a corrupted form of in and of itself and I think this is the case in the example given by the asker of this question.

In and of itself is just an emphatic form of in itself, meaning:

apart from any connexion with or relation to others; absolutely

The expression in and among itself, although rare in published works (9 hits on google books), can have a distinct meaning of its own. For example:

Unstoppable, it shoved us toward that mass of steel ribbon that curled around and around in and among itself like a gigantically long finely sharpened double-edged sword.

Here it means something like convoluted.