I fixed my machine!
Oh my, I can't believe it. It seems that the bobbin housing had jumped from it's mooring and was shuddering about, I just followed the maintenance recommendations in the manual and now it's sewing beautifully again. So, I should have photos of the quilt tops for you soon. I'm going to piece the warm one first because I am very happy with how that has come together. I think I will fiddle with the cool one a little more, perhaps I will add some 4-patch blocks to that one or put a few friendship stars into it. There's certainly no shortage of possibilties!