Holy Moley, when was THAT?
All those zigzags didn't get translated to existing.

Top third over the bottom two thirds (in area.)
You can see a split in the doorskin, at a right angle to the keel.
It's that top third that comes apart.

The 1" shaft of the real one is split for about a foot in length. Instead of two flat surfaces, one side of the split is keyed about 1/4" X 1/4" proud. Like the key in the groove of the tiller head. Only it's milled in the shaft. The mating half has a groove to receive it. When you put them together it's round again. Has three 1/4" thru holes for 1/4" bolts.

Basically, the blade is halved more or less in conjunction with the split shaft. The strap core at the trailing edge has some machine screws holding it together.

The bottom part is normal welded strap and foam. The shaft is whole down here of course and the gudgeon will pass around the shaft here. near the top of this section. It's about half way up the keel. Naturally I had to fiddle here too. In this case it is not a strap but a split casting that hugs the shaft. It is to be bolted thru the keel in such a way that one side only will detach when unbolted. We'll see.

Generally, the 1/8' strap is welded to the sides of the shaft and ground back at an angle. If you swung the rudder in its theoretical 30 to 35 degrees very little of the strap enters the channel of the keel. But I'm talking thru my hat because 338 has a reworked keel/rudder interface. The heads of the nuts and bolts will swing into the channel space - barely. Also I knew I needed the option to wrap the shaft in glass. The channel has an 1 1/2" radius. Allowing 3/16" if needed around the 1" shaft for wrap.