Okay, once you find and correct the exhaust leak, you can add, as necessary, atmospheric supply to the ER. That way, you can keep the deck door closed.
Throttle and shifter are controlled from the pilot house I hope.
Is that a chemical toilet or does it go into a black water tank?
I understand you never will and never want to make the boat shine like a new penny.... it is a work boat but, you want to be comfortable too. You can dress it up inside with some teak cabinetry?
Maybe flowers on the curtains ? LOL NOT!!
The goal is to make the boat presentable to your guests and comfortable for you.
How many berths do you have now?
You may consider reducing the berths, enlarging the head and making it a dry head ie separate shower compartment and a 2nd reasonable comfortable stateroom.
In the ER, what is that white tube hanging down into the ER space? I would suggest that be relocated or secured properly.
WE are all looking forward to more interior pictures.
LOL Nice cook stove. Get your sack of money and we will spend it for you. Please, when you have time, draw up a current floor plan with approximate dimensions.
The effort, IMO, should be to change the interior so when folks enter the boat, they will be surprised and excited.
Ah for the rest of us, 1.5tons of diesel equals approximately 460US gallons, I think. That will get you along way with your engine.