< u > < i, m, n, u, v, w > = < o > < i, m, n, u, v, w >

If u is contiguous with i, m, n, u, v, and w, u becomes o, thanks to stroke letters.

http://en.wikipedia.org/wiki/Typeface_anatomy

um: cumun (come),

un: wunder( wonder),  munuc (monk), tunge (tongue), hunig (honey)

uv: lufu (love)

14th cy, French convention for long u: ou, leading to confusion: ou + vowel = ov + vowel

u as /v/ intervocalically: loue (love), Douer (Dover)

final u = w

u, v, w: vowel representation

v for /u/, word-initial, common: vre, vsis, vngodlie

u for /u/, word-medial, common

w for /u, word-final

w for /u/, word -inititial: scottish ws, wnder

u for /u/, word-initial, exceptional: unitie, unto, use, utterlie

w for /u/, word-medial: cwmyn, fwrth

v for /u/, word-medial: cvmpany, cvrage

u, v, w: consonant representation

v for /v/, word-initial: French: voce, vanite

werray

medial Fr: remowe, resauit, resavit, reprevis

alternation of old Eng intervocalic f: gave, gevin, have

old Eng w

Edinburgh history of Scottish language

Origins and development of the English language

http://hotword.dictionary.com/w/