I have had one of these for almost 12 years, it was the first instrument I learned to play before picking up the alto sax and remains in my possession today. I have one that was made around 1977 or so and was actually a wedding present from my father to my mother, so it holds a large sentimental value to me more then anything. But I love it, and while I am not the best clarinet player, I keep this because of it's value to my family and the amazing sound it has. One thing I never was fond of was student clarinet models as well as the small bore models on the market today which are just whiny sounding by comparison, must be a symphony player thing to like squeaky sounding clarinets. I find it's incredible for dixieland types of music and I still feel like it resembles more of that Benny Goodman type of sound. I did not start playing the horn until after I started learning on a student horn at school, but quickly convinced my parents that the school horns were terrible to play in both tonality and build quality. I would assume my dad bought it second hand as my parents have only been married for about 26 years, and my mother was pregnant with me on their honeymoon and I am 25. My mother used to play in a symphony before I was born.
My understanding was the Series 9 models were large bore and I have always noticed it has a much more robust sound and a less shrill upper register. I use a crystal mouthpiece with mine out of preference, it keeps the high end smoother then a hard rubber that I used for quite some time. The only real wear was a chip on a sound hole cover which was filled in and it plays just fine so it's nice and sealed, otherwise it's in incredible shape for an instrument that was made some 34 years ago or so. For what it's worth, I would always recommend one of these even if it is second hand, they generally don't sell super high compared to other Selmer products, but they sound amazing and play great if you got a good condition one. My understanding is their resale value isn't very high, but I have no plans on selling mine as it's been passed onto me from my parents and will no doubt get passed down to whichever kid I have that wants to play music.