I just bought what I think is a cx100 at the flea market (it would be my very first Esterbrook). It is a solid blue lever filler, all soft plastic including the section. The cap is loose and the threads are worn out and it came with a 9550 nib. Cost me a little less than 5 dollars. Does it sound like a cx100? Is there any hope of fixing the threads? Did I pay too much? Thanks for your help guys!