We knew there was significant rust in both rockers and opted to start on the driver’s side. After starting to cut damaged metal away we discovered a fairly common sin in MGBs – someone installed new rocker panels directly over old, rusty panels. It was a cheap fix but the rust quickly migrates to the top panel and shows up again a few years later.
Cutting the sill and dogleg away carefully revealed significant damage to the membrane between inner and outer rockers, as well as the castle.
We kept cutting until we had the outer rocker and membrane completely off the car. Removing the rear portion of the rocker is tricky and we’ll tackle that with an air chisel later.