Re: func_train stopping
If you wont the sound to be played only one time, you have to check the "not toggled" flag of the ambient_generic, and give a specific name (targetname) so it can be triggered at a specific moment.
Note that the "not toggled" flag tells that the sound is not looped.
With Jed's HL Model Viewer you can see HL models and you can see also all the animations.
Sorry, but i don't have understanded what you have to do with Goldwave. Can you explain better?