go with the perfab corners. if you're covering a rusty area with a panel and are not going to weld scrape the loose paint off and hose the area with lithium grease before installing. it's the easiest way to keep the rust from continuing. optimally you'd want to take it down to bare shiny metal and prime and paint, but if you were that involved you'd probably be using a hammer and dolly instead of patches. use steel rivets/fasteners.

94 yj 456gears, detroit locker and 30 spline axles out back, 33" bfgs