No politics all day, just a pile of CDs I haven't heard for a long while. And I think I've cracked the rudder. The existing long pintle is heavily made and well thought-out, so it was a case of designing a rudder and tiller to fit.
Keeping it as simple as possible, I've got it down to seven pieces cut from 5mm mild steel sheet, a couple of bits from 1/2" bar to be machined, a 2" plank of Iroko for the stock and a piece of Ash for the tiller. Now I can cut and rout the timber, I can ask my brother to machine the gudgeons and I'm told the fabrication shop next to the boatyard can make a decent job of the cutting and welding.