Originally Posted by Grinnin
As you say, it's cheap, simple, and effective. And quick. Your foam is a good solution too.
I tried to make the inside smoother.
I used Tee nuts inside my side cases and in the top box. In the side cases I use a pin spanner to turn the stainless Tee nuts themselves on stainless carriage bolts (with stainless fender washers and black RTV). In the top case the tee nuts are sealed into the interior paint and I use allen bolts going up from the bottom.
Pic of a side case here. (The top box is far simpler inside.)
I just wanted to mention an alternative.
Anyone can take the helm when the seas are calm.