The usual word for “and” in the 1910s was ᴱQ. ya(n) (PE15/69, VT40/8). It was derived from the early root ᴱ√YA (or possibly ᴱ√(D)YṆTṆ) in the Qenya Lexicon of the 1910s (QL/104-105). In his later writings, the usual word for “and” was Q. ar, but something like ya(n) survived in the “dual” conjunction yo “both ... and”.
Early Quenya
vaine
noun. sheath, pod
vaino
noun. sheath, pod
ya(n)
conjunction. and
A noun appearing as ᴱQ. vaine “sheath, pod” the Qenya Lexicon of the 1910s under the early root ᴱ√VAẎA “enfold, wind about” (QL/100). It was followed by -o, probably indicating a variant form [vain]o; compare ᴱQ. vainole “quiver”.
Neo-Quenya: I would retain ᴺQ. vainë “sheath, pod” for purposes of Neo-Quenya, based on the later root ᴹ√WAY “enfold” (Ety/WAY).