Skirt pattern lengthening

The challenge to lengthen this pattern from 28" to something longer - at least 33".
So I set about with a red pen and a ruler.

I have managed to add 6 1/4" which I think will make the finished length something like 34 1/2", a little bit long maybe even for me (I am 5' 6") so that will be quite long on me.
It seemed simple enough adding on at the top and bottom of the first panel (1" each), 1 3/4" at the bottom of the centre panel and 1" at the top,. and then 1 1/2" at the hem. I left the upper curved seam of the lower panel alone. The tricky bit was adding the appropriate amounts on the corners of the centre panel - where it joins the hem and the waist - to make it come out level.
I think this is maybe where its confusing (it sure was for me) and there is a LOT of sellotape sticking little pieces of paper back there! I think I have got it right now, though I am having great trouble taking a photo of it all to show what the result looks like.

Having done that I am seriously wondering whether the simplest way would have been to just make the centre panel wider by cutting it in half on the cross grain (90 degrees to the grainline) and spreading it the required amount - that would have left the waist and hem un-messed with, though would change the visual proportions of the skirt if that centre panel is larger. Marked in green on diagram at left.