Digging deeper.

Take a look at the factory pies cuts...laid back with what I would presume from a hammer/punch or both. Doesn't look right to me. Were they all at right angles from the factory? Anyway another question has arisen. Is the housing only anchored at the back...if so I'm no contortionist so how does one get to handle and nuts/bolts to the back (interior) of the body bed panels to secure the housing...etc?
Appreciate every ones input.
George