Yes they seem to be water proof. I glued the gasket onto the gasket surface with silicon adheasive. You can do all sorts of things to the lids for more storage, just keep about one inch around the outside for gasket surface. I don't like wasting the space in the lid, but didn't feel like messing with the second one.
The other 10% are sociopaths , serial killers and KLR riders. You wont get much sympathy from them.