I’ve had a lot of goes at this, ending in general exasperation.
Finally, I seem to have got an assemblage of bits and positions giving an alignment which might, MIGHT, allow photographs to be taken through the eyepiece without wobbling all over the world. This is a 35mm eyepiece in the cheap-and-cheerful barlow, with the camera platform gadget cranked up and back pretty much as far as it will go. It thinks it can photograph the twigs on a tree off in the next field.
However, it’s putting a bit of a strain on the tube, and I don’t know how the motor will cope with this great lump on the side. Another point: it took about 40 minutes to get it all lined up. I have grave doubts about my ability to get the whole assemblage out through the door like this, but on the other hand, trying to put it together correctly outside in the dark and with cold hands sounds impossible.
And even more to the point: it would be very useful to have a nice obvious slice of moon to practice on.