Is there any way to get the voice pack to work without the SCP?
If you want to go through the original campaign and rename all the voice file references to the new system, sure. However, you're better off just using the SCP, as suggested. The entire point of this project was to update an old favourite; I don't particularly want to go back to the ugly, slightly buggier FS2 Retail version. SCP is the future, baby.
Strange problem..
All I can suggest is a new pilot - after that, it's beyond me.
Anyway, I'm glad it's going well (with one or two exceptions, unfortunately) and I'm happy the voices have been well-received. I was very impressed with the quality of the volunteers' submissions, and the depth or range that each individual actor brought to his role or roles. I hope I've done the campaign justice. Of course, my secret hope is that a few years from now, someone will say "Y'know, Derelict's a really good campaign... wouldn't it be nice if it had
custom command briefing animations..."
But for now, this is enough.