Sorry to hear about your problem and it does sound like a big one.
I had a diesel leak on my first boat, and the rear berth cushion got fuel on it.Also, it has been leaking for a while (1-2 yrs probably), so all the upholstery inside the boat smells of diesel, as does the interior teak and everything else. We have taken off all of the upholstery that we can so as to air it out. Realistically, if we take care of the cause of the diesel leak, will we have a chance of ridding the boat of diesel smell? Are there any products that you would recommend to get diesel smell out of upholstery, teak, and wooden flooring?