I over-drilled all the holes, taped and q-tipped epoxy throughout.
At this point, it was obvious I needed to do something to "snug" the fit better. I wet out the butt end and added fiberglass mat over the part that was carved out, and then wrapped a couple of layers of cloth all the way around the tiller. Over that, I added a layer of wax paper and then clamped the tiller fitting onto the end of the tiller.