All good stuff chaps, thanks for all the tips.
I setup the EQ6 in daylight yesterday as the forecast looked half promising (compared to rain, I'll take it!) and stuck the C11 out to acclimate once the Sun had set.
Still need to go through my data for the evening, but I made a couple of tweaks to my finderscope which helped and I also used an alternative eyepiece to help centring the subject before swapping out for the cam. I also swapped my Click lock diagonal for a conventional compression ring one, as I think the twisting operation might have contributed (on top of the single arm mount I was using the other night). The chip gives about the same field as a 7mm eyepiece, so this already fun with a native focal length of 2800mm, before I start thinking of Barlowing
With the subject centred, I carefully watched out for drift (backlash?) and adjusted to make sure it stayed centred, to give me a fighting chance of getting it on the chip! For the most part, it worked. A bit of a fumble, but the experience is good.