Do you agree with my rationale below? This is with regard to British punctuation. The specificity of this particular question has not previously been posted.
'I need to visit the mall', said Aunt Emma, 'to pick up some party supplies.'
(The comma goes outside the introductory quote {'I need to visit the mall',} because it is not part of the original sentence. The original sentence isn't 'I need to visit the mall, to pick up some party supplies.' Logically, a comma would not follow the word 'mall' in that sentence; hence the comma goes outside the quote mark in the introductory quote. Make sense?)
But if the sentence were 'I need to visit the mall,' said Emma, 'but I need to stop by the bank first', the comma would go inside the quote mark (in the introductory quote). This is because the comma is an inherent part of the original sentence ('I need to visit the mall, but I need to stop by the bank first.'). The comma separates two independent clauses connected by the coordinating conjunction 'but'.
By the same respect, 'Well,' said I, 'I'm sorry, but I can't do anything there' is correctly punctuated with the comma inside the quote mark in the introductory quote. The reason is that a comma naturally follows an introductory expression like 'well'.
And, finally, the comma would go outside the ending quote mark in the following example: 'Good-day, sir', said I. The reason is that the comma is not part of the initial quote.
Based on this infrastructure, I'd also propose that the following are punctuated correctly per British criteria:
•When Mike said 'Be careful what you wish for', Janet listened. (Not sure whether a comma follows 'said' here.)
•I won't accept your proposal', Dave said.
(The comma goes outside the ending quote mark here because it technically is not part of the original sentence. The original sentence would require the full stop (i.e. 'I won't accept your proposal.').
Is my explanation valid, and are all my examples punctuated correctly?