It can be pinned down a bit more tightly by looking at The Enumerator's District Description for NW Chelsea, District 10.
The 'beat' the enumerator lays out says this:-
#s 256 to 178 (junction) Kings Road
#s 1 - 4 Omega Terrace
#s 1 -5 Alpha Terrace
#s 1 -53 Blenheim Street
#s 1 - 4 Markham Terrace
#s 1 - 12 Brewer Street
#s 22 - 33 Upper Manor Street
Taking this information, together with my 1862 Stanford's map as compared to a modern map, this places Omega Terrace somewhere on the north side of King's Road between what is now Sydney Street and Markham Street:
http://tinyurl.com/2aph87 (use tools to zoom in)
Upper Manor Street (as was) is now the part of Chelsea Manor Street which runs to the north of King's Road
Blenheim Street (as was) is now Astell Street and Burnsall Street, again to the north of King's Road
Markham Terrace is likely to have been close to Markham Square and Markham Street, again, both to the north of King's Road
Brewer Street I can't find in 1862, but the area between Upper Manor Street and Blenheim Street was occupied by the Anchor Brewery, so Brewer Street may have been connected with that.
I don't see Alpha or Omega Terrace in 1862, but they may have been rows of properties on, or slightly set back from King's Road itself. In 1862 there were terraces named Manor Terrace and King's Road Terrace which fitted this description.
Anna
