My machine is also a 19233. I took the advise and cleaned the machine a second time, but I never found any other needle parts. I had my dh take a look at it yesterday - he's not a sewing machine repairman, but he is a mechanical engineer so I figured he would figure it out. Once he figured out how everything worked (lol, he was so funny to watch because he wouldn't listen to me, he had to figure it out himself. He was like a kid with a tinker toy, lol) he zeroed in pretty quick on the problem. My hook appears to just
be rubbing on the bobbin assembly - just enough that you can make out where something has rubbed but not enough for there to be a gouge or anything you can see unless you really
look. His opinion was that it will be ok for the short term so I can finish my projects, but then I will send it off to the repair man to get looked at. In the mean time I put just a drop of machine oil on the rubbing spot and the sound went away. Thanks to all of you who replied, you guys are great.