History of Neither Nor - Negative Meaning with Negative Verb Structure

Solution 1:

To answer your question, as far as we know, there was no time in history when

• *Neither George nor James doesn't go to school.

meant the same thing in English as

• Neither George nor James goes to school.

Logically, Neither P Nor Q means                   [¬P ⋀ ¬Q]   (Not P And Not Q),
which is equivalent by DeMorgan's Law to   ¬[P ⋁ Q]       (Not [P Or Q]).

Solution 2:

The parallel structure of neither-nor is:

Neither [noun 1] nor [noun 2] [verb].

Each noun has the verb individually applied to it.

There is nothing about the grammar that necessitates the verb be of a positive form. It typically is only out of concern for comprehension that the negative is avoided. It's not that it used to be in existence but no longer is. It still is in existence if somebody wants to use it.

For instance, this is grammatical:

1. Neither George nor James doesn't go to school.

Which would mean:

2. Both George and James do go to school.

But while the first sentence is grammatical, it's also difficult to parse and something that wouldn't normally be said. Far more often than not, the first sentence would be rephrased to something like the second sentence. (Also, in the second sentence, the use of do would be dropped. Unless you're emphasizing it, it's unecessary.)