county seats that never had a state highway

[NE2]

The specific location of St. George is a better particularization of where the seat is.

Applying this argument to other large cities, you'll probably find that many supposed county seat neighborhoods are not actually served by any state highways. For example, does New York County's seat have one? What's the county seat - Manhattan? Lower Manhattan? Or the "Civic Center" neighborhood?

And what's the county seat of a consolidated city-county, if not the city?

[empirestate]

The specific location of St. George is a better particularization of where the seat is.

Applying this argument to other large cities, you'll probably find that many supposed county seat neighborhoods are not actually served by any state highways. For example, does New York County's seat have one? What's the county seat - Manhattan? Lower Manhattan? Or the "Civic Center" neighborhood?

The seat of New York County is given as Manhattan, probably because the Gazetteer doesn't register any placenames at a finer resolution than that.

You could indeed apply the argument to other large cities, but in most cases you'll find the city itself to have been designated as the county seat in a more formal manner than we have here; the seats of NYC's borough/counties aren't set down legislatively, as far as I'm aware.

I'll leave it to you as the OP to make the judgement on Richmond County; as I say, I've already discounted because it used to have NY 439. I am curious to know what you decide though, since the only official source I've seen says its seat is at St. George, and I'm interested to know if you've deduced it to be elsewhere.

(For others' edification, by the way, the other NYC county seats are:
Queens Co. - Jamaica (unincorporated)
Kings Co. - Brooklyn (borough)
Bronx Co. - Bronx (borough)
New York Co. - Manhattan (borough).

[Alps]

And what's the county seat of a consolidated city-county, if not the city?

This.
Second.
Bump.

[empirestate]

And what's the county seat of a consolidated city-county, if not the city?

This.
Second.
Bump.

I don't know, as I would also say it's the city. But we were talking about New York, which isn't a consolidated city-county (it's a city consolidated into 5 counties), so I didn't mention those. As for each borough/county acting as a consolidated entity in itself, indeed there are the three whose seats are themselves. But the seats of the other two are unincorporated areas within these consolidated areas. That's according to the only state source I have at my disposal; the only other source I could think of would be NACo, but they don't recognize the counties of NYC, presumably because they are actually branches of the city government and not functioning counties in their own right.

[lordsutch]

I don't know, as I would also say it's the city. But we were talking about New York, which isn't a consolidated city-county (it's a city consolidated into 5 counties), so I didn't mention those. As for each borough/county acting as a consolidated entity in itself, indeed there are the three whose seats are themselves. But the seats of the other two are unincorporated areas within these consolidated areas. That's according to the only state source I have at my disposal; the only other source I could think of would be NACo, but they don't recognize the counties of NYC, presumably because they are actually branches of the city government and not functioning counties in their own right.

Eh? There's no such thing as an unincorporated area within the boundaries of an incorporated municipality (in New York, cities or villages are examples of municipal corporations). Jamaica and St. George are neighborhoods of the city of New York (specifically neighborhoods of the boroughs of Queens and Staten Island), not unincorporated areas.

[empirestate]

I don't know, as I would also say it's the city. But we were talking about New York, which isn't a consolidated city-county (it's a city consolidated into 5 counties), so I didn't mention those. As for each borough/county acting as a consolidated entity in itself, indeed there are the three whose seats are themselves. But the seats of the other two are unincorporated areas within these consolidated areas. That's according to the only state source I have at my disposal; the only other source I could think of would be NACo, but they don't recognize the counties of NYC, presumably because they are actually branches of the city government and not functioning counties in their own right.

Eh? There's no such thing as an unincorporated area within the boundaries of an incorporated municipality (in New York, cities or villages are examples of municipal corporations). Jamaica and St. George are neighborhoods of the city of New York (specifically neighborhoods of the boroughs of Queens and Staten Island), not unincorporated areas.

They are within incorporated territory, but are not themselves incorporated. (There is no "Village of St. George" or "Town of Jamaica", in other words–at least not anymore.) It might help you to think of the term "non-incorporated" rather than "unincorporated".