The Early Qenya Grammar (EQG) of the 1920s had several different words for “thousand”. The manuscript version had ᴱQ. {súme >> húme >> ellume >>} húme “thousand”, originally meaning “a great number” (PE14/50 and note #56). The typescript version had ᴱQ. maite (maisi-) “thousand” (PE14/83).
Neo-Quenya: For purposes of Neo-Quenya, I use ᴺQ. húmë “thousand” since Q. maitë means “handy; handed” in Tolkien’s later writings. Some Neo-Quenya writers prefer ᴺQ. mencë “thousand” as a hypothetical cognate to S. meneg.
A word appearing as ᴱQ. ellume “✱one time” in the Early Qenya Grammar of the 1920s, a combination of ᴱQ. er “one” and ᴱQ. -llume “times” (PE14/51, 84). This document had an alternate ᴱQ. eru “once” as an adverbial form of er, also used as a prefix (PE14/51, 84).
Neo-Quenya: Since both er “one” and ᴹQ. -llume “time” survive in Tolkien’s later writings, I would retain ᴺQ. ellumë “once, one time” for purposes of Neo-Quenya, but eru “once” clashes with the later name of God: Eru “the One”. Tamas Ferencz instead suggested ᴺQ. millumë “once” using min “one [for counting]”, but I prefer to stick with the attested form.