Sheri,
I have two of the Singer 9W-7's. They are mechanically identical to the W&W D9 so what I say for mine applies to yours as well.
Most of what I was going to say has been said, so I'll just embellish things a bit.
First the machine rotates opposite most other Singers. Nuther words the hand wheel rotates away from you rather than towards you. Makes no difference in actual sewing, just takes some getting used to.
Needles are a pain, the machine takes the 127x1 and they are difficult to find. Both my machines sew better with the 127x1s but will work OK with the MY1014s. You have to manually index the MY1014s because they are a round shank needle. They work because the shank is smaller than the 127s. The 15x1 will not work on an unaltered machine because the shank is larger than the 127.
If you know a good qualified machinist you can end the needle problem for ever. That requires removing the needle bar, taking off the needle clamp and removing the uber tinsy needle index screw. Then drill out the needle hole just deep enough for the 15x1 to seat in to the correct depth. After that the tiny index screw will have to be dressed down to fit the larger diameter of the 15x1, then reinstalled. Then simply reassemble the needle bar to the machine and adjust the needle timing as needed.
Doing it this way will allow you use the 127x1, MY1014 and 15x1 interchangeably.
Bobbins are a bigger pain. The bagel or donut bobbins are hard to find and cost a fortune. If your machine came with any, put them in a safe place with the machine and don't let any fingers other than yours near them.
eBay, and luck is about the only places I know of to find any.
The D9 / 9W-7's rotate very easy. They are a very simple design, but do like oil. So when you get it clean, keep it oiled.
Do your best to not let it spin backwards. They will break the thread, and can break needles if that happens.
That's a nice machine, once you get up and running I'll bet you end up loving it.
Joe
Last edited by J Miller; 01-22-2015 at 09:02 AM.