Hey Andybear, in answer to your questions, the grey bulkheads are made from high density foam rubber that i picked up an off cut from clark rubber for cheap, about 25mm thickness.
first of all cut out the right shape using cardboard, then tracing the shape on to the foam, cut it out and glued it down with 'bostik clear seal' which is what i used to glue down the f.finder transducer as well. You could easily do the same to your tempo wells, or any boat for that matter.
in the predator the front one is good for keeping fish contained, i can even put a bit of ice in there to cool the fish down, then after i have killed my catch shuffle forward and throw the fish under the front hatch.
hope this helps