Roger Winarski (BB) had an example of his tiller offerings on the shelf at the Maine boatbuilders show. The nearest match is a clone of the Rostand pattern with the 1" hole thru drilled (you can see a sketch in his on-line catalog). Thru drilling reduces the cost of machining. technically i don't see a problem with that approach. in fact it might make removal easier since a bearing puller could be used to extract the tiller head if required.
I agree that 40 years on, the tiller head clamp assembly doesn't get the job done. Mine's currently tapped for two allen screws that bear down on the keyway. If for some reason my new part from Historical Arts doesn't clamp adequately... it will get the same allen screw fix.
