Ok, its not a -7 or -8, but I thought it may be applicable. We installed access panels in both outboard leading edges to inspect our fuel return fittings that are located in the outboard rib of each tank. These panels seem to allow easy access to the outboard portion of the tank through the lightening holes in the inboard rib of the leading edge (visible in the pic).

Oh yeah... the panels are those available from Van's, and come with the -10 wing kit for stall warning access.