Please can someone help me identify this story:
- It was a novella and I read it in an anthology in 1995 (but the book was quite tattered so it may be older that 1995)
- It was set in the near future on Earth, where rich people are very privileged and poor people live what we would consider to be fairly ordinary lives
- The protagonist is a teenager called Boy Wonder or Kid something - his genes have been altered to make him look like a much younger boy
- This genetic alteration process is called 'twanking' and rich people do it all the time just for fun.
- His best friend has also had his genes altered to make him look like a dinosaur - he's called 'Stennie' after the kind of dinosaur he resembles.
- He meets a girl who is a descendant of Scott Joplin and she teaches him the benefits of an 'ordinary' life without all the trappings of great wealth.