singer did the slow take over on wheeler Wilson, something like 5 yrs. Then put the name singer ( 1905) on the machine untill that supply of parts run dry. That ended the 9 series machine.
it's the D9 and Bridgeport. making me think singer had contorl of WW at that point . WW's commercial line started with a D , but ( I think the home machines started with a W as in W9 , then singer came around and change this to a D9 yet had the name wheeler Wilson on the machine, then in 1905 /? put the name singer on the machine still using D9 . your photo won't open for me. I can't see the cabinet
yep I uncovered mine it's W9, it doesn't matter there all the same parts. They are about twice the machine that a singer is ( quality)
google wheeler wilson