Right you are Icarus2001, I had forgotten about that. They removed the forward toilet (to the relief of the cabin crew I believe!) and moved the rear galley cart stowage forward to where the toilet was to assist in squeezing in another row. If they didn't do that I think the new seats would of only allowed either one extra row or one and a half (the half being a row of three seats instead of five).
In regards to the seats I do not know if they are the same type that the FAA have told Delta to remove within five years due to crash survivability concerns.
The aircraft used on "the golden triangle" have 110 seats. 2 dunnies one rear for economy and 1 for business (and flight crew) Q steaming for entertainment.
As for long in the tooth, maybe compare the age of them with the age of some of the other aircraft in the QF fleet?
The QF 717's vary in age, the first ever 717 produced was 1999.