I have been looking on ebay for a Sengbusch self closing inkwell. I notice that none of them seem to have (what I assume should be) a little spring to make the middle seal thing pop back up (the self closing part). Are they supposed to have a spring that forces the middle seal back up? Or am I missing something about how it works? I have PM'd several people that are selling them, and they all say that there is no spring present....but they also say that they don't know how it works or if it works correctly. So who knows..... Thoughts? Chris