Lane, looks like your U Bolts are rusting away badly. Now is the best time to replace them, especially if you have to cut them off (I had to!). Here is the BEST place I found online to buy galvanized U Bolts, by far cheaper than certain Marine Parts stores or other hardware suppliers;
http://www.sturdybuiltonline.com/Galvanized-Trailer-U-Bolts_c_188.html
BTW, nice trailer... Mine is very similar with that same I-beam construction. If you want a better way to fit the bunks to the hull, rather than in the water, try this; Use a cherry picker in from the side to lift up the bow eye, then two boat stands supporting the stern (place the pads close to the transom where the fiberglass is thicker, otherwise you'd need a cradle). With the hull supported this way and the wing keel resting on the pad you can adjust the bunks however you need to, also move the hull forward on the trailer first if needed, get that weight as far forward as possible!
This method is typically what you'd need to do to get the hull off the trailer and on to stands and then back on again for bottom paint of whatever. Since I know your hull is in the water you still need to get it out, so you'll have to do your best guess with measurements off another C22 wing-keel trailer.... set it up as close as you can first and pull her out. Do your adjustments on the hard in the parking lot, not in cold water.... that would just suck.