Well I might as well add my 2 cents to the mix as well, FWIW. While I wouldn't go the route of Steve's suggestion of turning the horn into a bidet or urinal--creative as those are
--does the world really need another saxophone lamp? Do you? If you do, then by all means make yourself one.
By now I'm sure you've got the general message conveyed by everyone here: 1. Don't spend money getting it fixed, you'll never recoup it. 2. If you're going to sell it, sell it as is, or trade it, but don't expect much for it. It ain't worth much. 3. If you want to learn to fix things, this is a good project you can experiment on, and you won't ruin anything of value if it doesn't turn out.
BTW, if you'd post a couple of pics of this mystery horn, and include a partial serial #, with the last few digits of the serial # X'd out, we can tell you more about it.
Since 2000, I've had a straight neck, New Wonder Series II Conn that's in dead mint condition. I got it from the original owner. My main genres of music are rock and blues. Needless to say I haven't used it in those. The voicing is just flat-out wrong. Although I also fronted my own jazz band for a while, I never used the C mel in that. The style of jazz we did--lounge type standards--didn't suit the horn either. Nor did the Latin jazz and even big bands I worked in.
The only 2 times I've ever used the horn outside of the privacy of my own home, were when I took it to a seniors home, and played over the shoulder of the piano player. I took it there on purpose, just in case there were some residents who still remembered that sound from their youth. The only other time was when I took it to a friend's and played Happy B-Day for her.
Yes, there are lots of people who will say that they use their C mels all the time in this band or that, and that they use an alto or tenor m/p. However, I use a Runyon C mel m/p and get a C mel sound. That traditional sound, doesn't fit in with today's music. I've tried both alto and tenor m/p's on my Conn, but I don't like the sound. An alto or tenor sax sounds much better.
An argument I frequently encounter online is that people like to play C mel just for the sake of not having to transpose, or for being able to play in "easier" keys. But that just doesn't make sense either. If you're a musician, you're expected play in all 12 keys, not just in the "easy" ones. The only way all 12 become easy, is by practicing them. At first even G or D were difficult for us, but eventually we learned them. So too will F# and C# be, once we get the fingerings patterns so ingrained in us that they become second nature.
So what does that mean for your C mel? Only you can say. Lamp? Trade in? Fixer upper? One thing is for sure, there are lots of pristine examples of C mels out there. Sadly, very few of them have an opportunity to get out of the closet very often. Mine included.