i am restoring a wayne 60. i don't have the front and rear flat panels but will have a local metal ship make them. the twist connectors, that hold these panels on, are still installed in the frame rail. my questions are: do i just drill round holes to accommodate these connectors or are they slotted holes? also, how do i install the second panel as the side panels are screwed in from the inside and once the first flat panel is installed i cannot get to the backside of that panel to install the connectors? help. thanks.