Thanks guys,
I'm glad I hadn't missed the point somewhere. I completely agree that there is nothing wrong with capturing the G/S from the procedure turn altitude (actually it's a base turn in this case). The FAF crossing altitude is there to cross-check the G/S.
For a LLZ only approach it would be necessary to descend to the FAF altitude after the base turn and then to potetially fly level until crossing the fix. There is no other way of determining your range from touch down (without DME).