I had a very interesting conversation with Jose the diesel tank guy, as referred from Richard the refitter, as referred from Paul the surveyor. Jose's main recommendation for tracking down my fuel leak is to pour in distilled water with food coloring and see where it comes out. I'll have to give that one a little thought, though I can definitely see the advantages of that over pumping 80 gallons of diesel in to find that leak and the watch my bilge fill up with it.
The tank and the engine mounts are definitely the top priorities at this point.
I guess what we're going to have to do is to re-up for another month in the condo before moving aboard. Hopefully we'll finally have the engine thing resolved by then.