Porch Weave on Uneven Rails?

I have a very nice rocking chair I would like to re-seat using a New England Porch Weave pattern. However, when I dismantled the chair, it turns out the original rush seat was woven onto a frame roughly 2.5" wide all around. This frame was then attached with screws to the front and side rails. I would like to eliminate the frame and just weave to the rails BUT, the front and rear rails are roughly 5/8" lower than the side rails.

Is there any way to compensate for this in my weave, or do I need to reconstruct another frame, weave on that and then reattach it to the chair?