I am not sure when Ermington was absorbed into Parramatta Council, but back in 1918-1919 it was a separate council area.
Sands Suburban 1918 from page 313
(entries for 1918 closed Oct 1917, entries closed Oct each year for the next year’s publication)
Ermington and Rydalmere (Council) Area 1762 acres, population about 1000 with 250 ratepayers. (So two suburbs in that council district)
The Ermington and Rydalmere Council Chambers were on Victoria Road. (Town Hall was next door to the Rydalmere Post and Telegraph Office , on Western Side, Cnr Victoria Rd and Wharf Rd)
Pages 313 to 314 of Sands 1918 list all the households, by street (so not alphabetical by surname), and as far as I can see, NOT one entry has a house number, or house name).
Ermington Streets:
Atkins Road (Off Victoria St)
Ermington Rd (Kissing Point Road to Ermington Wharf)
Hope St (off Atkins Lane)
Hughes Rd (Parramatta River to Victoria Road)
Kissing Point Road (Ermington Wharf Road to lane, Parramatta boundary)
Spurway St (Kissing Point Road to Parramatta River)
Stephen St (off Kissing Point Road)
Victoria Road (Kissing Pt Rd to Spurway St)
Wharf St (off Ermington road)
Sands Suburban 1919 has Ermington and Rydalmere across pages 318 & 319. The boundaries are same as 1918’s entry…
" Commencing on the left bank of Parramatta River at its intersection with the eastern boundary of the borough of Parramatta; bounded thence by part of that boundary northerly to centre of Kissing Point road; thence by a line along centre of that road north-eastly, south-easterly, and again north-easterly to centre of Marsden’s road; thence by a line along the centre of that road, being western boundary of Ryde, south-easterly to left bank of the river; then westerly by the bank of the river to point of commencement" .- (That's the boundaries for both suburbs, not just Ermington
)
http://cdn.cityofsydney.nsw.gov.au/learn/history/archives/sands/1910-1919/1919-part4.pdf Cheers, JM