For Edith, don't forget that Spring/Autumn 1921 electoral registers for Oldham are online (England & Wales, Electoral Registers 1910-1932)
Medlock Street 1921 address search, 10 results
House numbers 2, 8, 10, 12, 14, 18, 20, 22, 9, 13
Schedules 112 - 122
Minus schedule 117, which I guess would equate to house number 16.