Originally Posted by Pierre
The letter gives the street adress and both room numbers of Mary and Elizabeth in metaphorical style and it gives a hint at Tennyson.
Tennyson wrote the drama Queen Mary and the drama includes Elizabeth as well as the Lord Mayor.
Now let's see if I've got this right.
The letter does not mention the name 'Mary' in any form of language, metaphorical or otherwise.
What it does is 'hint' at Tennyson and because it hints at Tennyson you immediately think of the drama Queen Mary which then makes you think of Mary Jane Kelly.
And because the drama also includes Queen Elizabeth you think of Elizabeth Prater and because it also includes the Lord Mayor you think of Lord Mayor's Day which is 9 November 1888.
Am I fairly summarising your thinking here?