I did just that in my 88' truck cab. First of all, I got myself a
cubby box.I then took a trip to the local DIY and bought myself a sheet of aluminium and some L profiles (also aluminium). I cut the L profiles to form a square to fit the cubby box wooden frame. I riveted the L profile frame to the sheet, which I had cut to the same size as the
348855 cover. In the sheet, I drilled holes that matched the holes in the seat base. I then drilled some holes in the sides of the L profile frame, put in the box and used regular wooden screws to attach it to the frame. Last thing was to use the cover screws to attach it all to the seat base. Old Smokey isn't at home at the mo', or I would post a couple of photos.