Sorry just a hanging photo at the moment.
I levelled up the back as planned and took 3.5" off the centre 'point' of the front droop tapering it to the right seam (that was a straight line anyway) which made the point slightly more to the centre then gently tapered the other side to where the droop started, somewhere close to the centre front.
The length was left as per pattern apart from the droopy point which was almost floor length on me before trimming!
Had numerous issues with zip, mainly user error as I haven't used on in decades, and having initially tried to use the wrong invisible zipper foot that was left from my original machine, almost 30 years ago.
The Kenneth D King YouTube tutorial was great, I had the foot he used already and the haemostats he talks about. Also substituted a longer (1") zip than pattern suggested which is part of the knack and have made a mental note to always do that in future!