I think Harringay is where people say it is. And no-one's said it isn't Vale Road to my knowledge - well apart from me by implication. No offence intended.
Trying to agree where a London area starts and ends seems to be a real mare. Surprisingly you're the first person to take issue with my pencil line around Harringay. I'm happy to flex it out to Vale. But I'm going to wait a couple of days just to see if anyone else has any views.
By the way, you say parts of Vale Road are in Harringay. Which parts? Where would you draw the line?
I have lived at the beginning (Green lanes/Hermitage road end) of Vale road for over 5 years and definately feel part of Harringay...use the park, shop locally etc. Although technically the top end of Vale Road (before the industrial estate) is just outside the Harringay ward boundary and just within the Seven Sister ward boundary, it is the Harringay side I interact with when outside of my front door.
This part of Vale road is also close to the borough boundary for Hackney and Haringey...close to lots of boundaries and keen to feel part of one!
Although I have not really looked into it, I have always thought it was bounded by Finsbury Park to the south, the railway to the west, Wood Green to the north and West Green,Tottenham to the east. Just seemed to make sense, but no doubt I will find there is some quirky historical definition based on the extent of the grounds of the old manor house, or similar.
Your definition is pretty much how I saw it (See the Google map, linked to on the panel, top-centre, on the main page). I don't think Manorial or parochial history helps alot because in the times when they were relevant there was no settlement here. Beyond the odd large house, ther was nothing until the 1870s. If any historical reference makes sense, it's probably the views of our Victorian and Edwardian forebears. But I honestly believe that a London area gets defined and redefined by the people that live there. I think going much East of the Google map certainly strays into West GReen territory and S Tottenham. Stretching South to the Western part of VAle Road kinda makes sense. If Vale Road West isn't Harringay, what is it?