The Wither Tracing for HP Swinging Fender Australian Stock Saddles is NOT done in the same position as a tracing done for English style saddles.
For English saddles, the tracing is done 2" behind the rear of the rear edge of the shoulder blade, when the horse is standing square with his head level with the wither. This is too far back for a tracing for HP saddles.
The reason why it is not done in the same place is that English saddle panels sit BEHIND the shoulder blade of the horse. The 2" margin allows for the shoulder blade to come back as the horse moves, without the front of the tree hitting the rear edge of the shoulder blade. However, with HP saddles, the shoulder moves freely, UNDERNEATH the panels, (in a similar way to English Free n Easy, or Roe Richardson Reactorpanel saddles) as they are much larger and sit further forward than an English saddles.
This means that the wither tracing is done further forwards too.