Thanks for the reply Jerry,

I am having a little trouble understanding what you are saying. Are you saying you would recommend the windows be brought to the outside of the sheathing (old LP) and then the typical 2 layer flashing system be installed? Without bringing the nailing flanges to the outside of the sheathing, I can't see how you could install the 2 layers of flashing (peel and stick) you speak of.

This is to panel siding, so there is no original flashing.

I think we are pretty much on the same page, except for the fact we explain and understand things differently.