parked by our MR Synergy in a MacDonalds parking lot south of Starved Rock State Park last summer.
From the damage in the OP's photos, much of the work would be spreading the split in the gunwale a bit, cleaning out any dirt, and then spreading some thickened G-flex into the crack. The crack would then be closed with spring clamps (no need for ultra force, just enough to bring the crack close to closed) and then let the G-flex set. I'm not sure the crack would need any additional reinforcement, but I might cut some narrow strips of 6 oz glass to lay over the top. After smoothing and cleaning, the strips can be wet out with G-flex. Some Glad food wrap over the glass and resin will make for a smoother final result.
I'm not sure if I visualize the damage to the opposite gunwale correctly, but it looks like it may be split crossways. This may require a bit more aggressive a repair. The first step is to clamp some wood pieces below the split to fore the gunwale back into line. Next, some filing and grinding on the outside of the crack will open it for one to work in first some non-thickened, and then some thickened G-flex. Keep the resin off the wood pieces, but don't take them out yet.
I would put 3 or 4 layers of fiberglass across the top of the split, the largest/longest first and so on with shorter pieces down to the smallest. Glad food wrap and allow to dry.
You know, you could epoxy a longitudinal piece of stiff wood, or white PVC pipe, right under the inside gunwale. That would protect the repair to the cross-split gunwale. If the PVC pipe is the right size, you can slip your fishing rod through it when you're not using it.