The W&W takes a 127x1 needle or a Boye 18. (In the case of Boye needles, the number indicates a style, and not the size)
I posted a thread here in the Virtual machine section a week or two ago that gives some alternatives and instruction on needles for the #9...
Keep in mind, if the machine isn't working, you can NOT ruin it by tearing into it! ;) How can you hurt something that's "broken"? :)
I could never find a manual online...the Smithsonian has a manual for an 8, a Meteor, and a parts catalog for a D-10 but nothing for a 9...I'll take pics when I get home from work tho, of how to thread the 9...it's a fairly simple process.