good job on the machine. i paid $20 for one not in a desk. For just the basic straight stitch i dont think you need a cam, but for the zig zag and other decorative stitches you'll need it.
As for the noise, compared to say a 15-91 it definitely is noisier, but if you compare it to a 401 it may be a little louder. Then compare this machine to a plastic wonder it is roughly about the same amount of sound. So I would agree with Mr. Miller in saying its about as loud as other machines with the exception of handcranks and treadles. lol
good job, keep her cleaned and oil she'll outlast you.