Welcome to the TF community.
As to your leaking portlight issue, I can make a small claim to fame re solving this.
It comes about as a result of ageing, hardening, and breaking down of the rubber seal around it. This is usually a square sectioned (in profile) type of special rubber, easily obtained from any decent boat chandlery. The trick is then to remove the old stuff, clean up the channel, and then mount the new back in, preferably using a modest amount of a contact adhesive, so it stays in the square profiled channel around the edge of the port.
This is much easier if you can dismount the port from the frame, usually there is a way to do this without too much trouble. Mine has split pins, but more modern ones might well use a different method. If you can remove one before you get any further, you can take it to the chandlery to get the best fit replacement material and further advice re tricks to do the job.