So, is it the case that you manually select an unsaturated star on the first image, which is then automatically followed, or is it that you click on the same reference star in all images?
As I recall, you use a Paramount, so your periodic error is much smaller than with my NEQ6 – the former approach would not work well with the NEQ6 as a star can shift quite a lot at one point of the gear cycle (I lose about 15-20% of 30sec exposures – yeah, getting the OAG going sometime is on the “TO DO” list).
If you were interested I could dig out the code for automatically working out interframe offsets, so you don’t need to do a manual selection at all. The C version I lost years ago but, I still have the Fortran, VB6 and Python code knocking about. Translating to C would not be a long job. I was sort of surprised that there’s nothing obvious to use for image alignment in AstroPy.