Yep - time to tackle those annoying twin rudders, with rudder posts so close to the hull you can not use typical tie-rod style linkages.
So, this was the arrangement I came up with.
The pivot post is cast-in-place in a lump of epoxy resin, which was poured into a taped in place thin cardstock mold. Cardstock and tape removed after expoxy had set up. Pivot shaft goes all the way down to the hull bottom itself, and I drilled a hole half way thru the hull, which the pivot shaft is screwed into.