Jed - don't know about the first, but the second seems to be an english spelling: Pronounce it as if it were english with the stress on '-gu.' and the '-ion' as in 'translation'.
The third might be the same as 'Petravore' in 'Eileen Og(e)'. The Dubliners who I know that song from pronounced the 'Pet-' as 'pet', the '-tra-' also as in 'translation' and the '-vore' as in 'shore' with the stress on it.
Take this only for serious if Áine doesn't answer - of course she's the authority for things like these.
Joerg