It looks like the best location to mount the TPS is on the rear of the manifold on the driver's side throttle shaft.  There looks to be just enough room between the distributor (whatever one I finally decide do use) and this location.

    If I clean this area up and make it perpendicular to the throttle shaft there should be enough material here to drill and tap a couple holes to mount the TPS sensor.  There isn't quite enough material on the throttle shaft itself to add the features necessary to drive the TPS but I might be able to add some brass and machine in the needed features.