about water level, could be some valve at bottom for water to release if it gets there any. nice idea for the box , but is that cone air filter is very good for doing its job for those engines?
and original air boxes are plastic , how bad could it be broken that it wouldnt be possible to fix it , you can glue plastic melt it and so on , many thing could be done from those boxes , redone them and such if you have ideas.