Melissa, I bought these:
Paula and Susan, you were both right: the little wheel in the middle of the balance wheel is the brake button. It just hadn't been used in so long it took a pair of pliers and a little elbow grease from my husband to get it loosened (don't worry--he used a soft cloth over the pliers). Once it was loosened, it worked perfectly.
Val and Tracy, here are pictures of the bobbin and part info, just in case anyone comes across something that might possibly be one of the bobbins I so desperately need:

Here's the length in inches:
...and in centimeters:
And the end, in inches:

...and in centimeters:

This is the part list from the manual:

This is the bobbin part number:

And I think, though I'm not sure, that this is the model number of the machine:

Oh, and Tracy--you scared me half to death with the broken needle thing. Would it be unreasonable to wear a flak jacket while sewing?
