Rhys and I had a look at cleaning the front element of the Tak, we used a hand-blower to blow off some dust, although stopped at that after reading about the potential for damaging the glass coating. Will investigate cleaning methods further, Rhys also adjusted the finder scope so that it is aligned with the ODK. We looked at aligning the Tak with the ODK, but this would require unmounting both scopes, disassembling the mount and drilling a hole in it, which we felt was not worth the marginal benefit.
Initially it was fairly clear around 9pm, then clouded over heavily around 10pm but then cleared up nicely for 11pm. I had brought my D750 just in case and I stayed until 3:15am to image M31 The Andromeda Galaxy.