Okay!! I have decided to take Poly's, butty's, and nugents advice and do both.
Seal the seat to try and make it watertight and then also raise the witches hat up by 60 mm just incase water does get inside the console. I will use neoprene like Mick suggested in another thread for my seat.
I have got quite a few other jobs to get done over the next few weeks like replacing my Garmin GPS splitter cable and also renewing my jockey and bench seat backrests which nugent is kindly making for me out of Fomex plastic, "no need to worry about wood rot" and then I will get them reupholstered
Thanks for all your advice k.