Riveted hull repair ?

[Tin-Can]

You may also want to give some local welding shops a call.  A professional welder may be able to tig an aluminum patch on the outside of the hull while it is on the trailer.  Biggest problem I can imagine with that is that if the hull is foam filled beneath the floor or if there is any other flammable material inside that could ignite from the heat of the welding.
I've used Bouchard in SLC before and been pleased with their results.

I know many have fished with you and know what the inside of your boat looks like, but I do not.  Do you have a pic that could give an idea of what the floor that is in the way looks like and how it is attached?

   The decking is marine grade plywood covered with vinyl and attached to the ribs and longerons by flush rivets. 
 I don't think there is any flotation foam between the deck and hull in the bilge cavity, but I can't be positive without pulling up the decking.  The photo below shows one edge of the decking against the live well box.   

    

All of the floatation foam is in the forward bench and the 2 rear side areas. 

         

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I had Bass Tracker TX17 (riveted hull) with exact same problem. I could easily pump out the seepage when fishing but when I left it tied to the houseboat at Lake Powell I had to get up in the middle of the night to pump it out or it would be way above the floor boards or worse in the morning. That's when I said enough. I didn't want to pull the floor out either so I crawled under it and found the seam where it was leaking. Was pretty easy to spot because the rivets were stretched to the point that they were actually loose in one area. I decided to try sealing it from the outside so from under the boat still on the trailer I put a nice bead of 3M 5200 along that area and let it cure. It didn't eliminate the entire problem but it slowed it way down. I could easily leave it on the water all night after that and only have a few gallons to pump the morning instead of 200 gallons like before. That 3M 5200 is pretty good stuff and even though it was right on the bottom of the hull, it never came off and lasted several years until I sold the boat.

  Seeing all of the rivet lines on the bottom of hull of my boat is difficult when it's on the trailer. The trailer bunks are positioned in such a way that one side of each of the 2 rows of rivets is sitting directly on one of the rivet lines.  
I have a couple possible places that could do the work I'm looking for.  If not, I'll attempt to do the work myself over the winter in the storage unit. 
Thanks for the info and input.

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I've never been there, but Roger's Performance Marine in Centerville sells Lund boats. Maybe they can help you.

   Yes, they took over Lund when Peterson in Ogden closed. I am waiting for a return call from them.