Thanks again Ian and thank you Dan.

I think the first thing I should do is to make up a lens board with my current TP shutter and do some speed tests. 1/60th or 1/90th or thereabouts if repeatable would be OK if I finessed the exposure with ND filters. The Ilex shutter looks an interesting option Dan, although I note it says they are accurate to within one stop which I think would be the case with my TP shutter although with more limited speeds.