The Seat BaseThe bench spring frame sits on ribs that provide strength to the spring frame as well as raising the seat's spring frame up about a 1/4" above the frame.
Spring Frame's Ribs The Gap Seat Frame's Center Rib This gap gives the seat cable mechanism room to work with out interference:
Passenger side cable mechanism:
Top View and
Front ViewDriver side cable mechanism:
Top View and
Front ViewThe implications of the above is that allowances must be made to use a plywood base for the cable mechanism to work. In other words, the plywood base cannot just be cut out and thrown onto the seat frame. My solution was to create a "
sub-floor" for a lack of a better term, I cut out two 1/2" plywood prices that fit between the seat frame's center rib and the outside edges with notches cut out for the cable mechanism.
Passenger Side's Sub-Floor Cut Out Driver Side's Sub-Floor Cut Out Front view at the seat frame's center rib With the sub-floor in place, I can now use construction adhesive and screws to join the sub-floor to the 3/4" plywood seat base. The bench seat platform is almost ready for the foam --- Still need to cut the front corners and add the clips
Base Glued and Screwed Base Glued and Screwed: Passenger Side Base Glued and Screwed: Driver SideCut the front corners and the seat base is basically done! (I still need to put the clips on the bottom, but that will be later). By cutting the sub floor and base together, the radius of the cut matches; no messing around. .
Base Glued and Screwed: Driver Side 
