Brian - nice piece of engineering, but is this not, as someone posted a few days ago, a case of overthinking non-existant problems? I note the bronze bush has been shortened by a fair bit in order to accomodate the seal, which is a downside. Also, the cork seal not only seals the shaft, preventing leakage into the dynamo chain area, but counteracts endfloat as well. With your seal modification I presume the cork is left out, thereby allowing endfloat? In my view, creating two problems to solve one that didn't exist.