[Destroyer]

First off, our most sincere condolences on the passing of your brother. Words can never adequately convey ones sorrow but be sure it is heartfelt.

As to your boat, you have a good one. I'm sure that you'll find that she handles better than any other boat you've ever been on in it's size class. The holes in the transom are a concern, but may or may not be a serious matter. Really, it depends on how long the transducer has been removed and how long the holes have been there. If they are recient you should be fine. If they are years old, it might be a problem. I would suggest that you drill several holes around thee area and look at the wood that comes out. If it's dry and normal you have no problems. If it's soft and spongy or wet and mushy that's an area for concern, and, depending on how much of an area it may need to be fixed for safety reasons. The fact that your boat is an I/O is a plus, since you don't have the weight of an outboard hanging on the transom. (Less flexing)
As far as the missing gauge, it's hard to tell. Normally there is a fuel gauge, a tachometer, a speedometer, engine temp and tilt/trim. But there could be more. or you might have a combo gauge that does several of those functions. A picture would really be a big help here.

Above everything else, welcome aboard. This is a great site with a bunch of really smart people, covering a wide range of professions. Oh, and did I mention... we love boat porn here, so any pics you care to share with us will be warmly received.