Re: how would you recommend repairing this hull
Well, I'll give a realistic assessment based on what I see in the pics.
The boat took a catastrophic hit. To make it safe (which hopefully you are going for) without spending unnecessary time on it, you will need to:
* Strip the interior out, including the deck, down to the hull structure. Check all structural members for cracking and green breaks (bending). Use graphite or a similar powder to look for cracking in the interior glass structure.
* Plan on replacing about half the side where the hull got hit. It's been hit hard enough to fracture the glass in a crack, so there's a really good chance some of the layers of glass have delaminated. If that's the case, you need to re-establish solid glass there, the easiest way will be to remove and re-create that section of hull.
A professional shop would do this one by taking molds from the other side of the hull and flipping them around.. the only way the broken side will look factory new again is either that plus a lot of sanding and fairing work, or getting the original factory mold and using it to make a half hull section as a replacement.
* re-structure the hull as needed once the hull repairs are in place, replacing stringers, deck, etc. with solid material. Check the hull for balance at this point, fore/aft and port/starboard, and ballast as needed to make it right
* Replace the interior, re-using what you can from the original
I know what you want to hear is that you can use X, Y, and Z to patch the hull after pushing it back into place, and I'm sure this boat looked like a great deal sitting on the blocks. But you can't shortcut it and still be even remotely safe. A boat like this, built for speed, needs a strong hull, and a half-done repair won't cut it. Even a repair that feels solid probably will fail unless done properly (the hard way) when this boat is under way.
Most people wouldn't try this repair because they can see how much work will be involved. I applaud you if you do.
If you don't try the repair, you can still get a good hull elsewhere (should be easy to find a similar hull needing mechanicals instead of hull work) and combine the two for a good boat. Or, part this one out and you'll make your money back and then some, and use that to buy one of these in better condition.
You can NOT just patch this boat and use it.
Erik
