If I saw ϖ in the wild I would have assumed it was an omega (ω) with a macron over it. Makes me wonder how many more varient Greek letters are out there.
https://en.wikipedia.org/wiki/Archaic_Greek_alphabets
Ϝ Digamma
Ͱ Heta
Ϻ San
Ϙ Koppa
Ͷ Tsan, Digamma
Ͳ Sampi