Joanna,
I have that same exact machine in that same exact cabinet. It is the one my SIL gave me that had been used for an aquarium stand.
They are wonderful machines.
Bobbins: Same as the FeatherWeights
Needles: 127x1, Boye 18 or MY1014B as Jon said. I've got a lot of mine from
{
http://stores.ebay.com/Jacks-SM-Repair }. There are other places to find them too. The MY1014Bs are usually only found in size 14s so I stock up on the old regular needles when I can.
When properly cleaned these machines turn much smoother and easier than the 15s 66s and others. Real easy to sew on.
It does have one quirk no one has mentioned yet; it rotates backwards from your Singer 66 and most others.
Not a problem really, just thought I'd mention it.
My 9W-7 is still languishing in the storage locker, but as soon as I get it back here I'll set it up to use it. For some strange reason I like using it more than I do my 66s.
Joe