I just recently bought a peterson rocky donegal estate pipe off ebay and have a question about it. As with any estate, the first thing i did was started to clean it. When i removed the stem i noticed it was a system pipe. Now what has me questioning is the stem. Ive noticed on some pipes there is a piece the protrudes into the system and ive noticed some that dont. The stem of my pipe has a little circular thing that piece that looks like it may have been longer and went into the pipe, but it looks like it was cut off. I was wondering if anyone could help me out? sorry if i incorrectly word anything, im a pipe noob. pictures attached.