There is something wrong here. Does anybody agree?
The OP wants to spend $100 or so making his trumpet look nicer, but will not pay for someone to remove the bottom cap. This is not to mention that a stuck bottom cap is usually only a symptom of something else that is going on; like corrosion.
What will he do when his lead pipe corrodes out?
I am so intrigued by this that I will write a blog post.