well I quickly set this up in the yard 2 hours ago and took some test shots. The Pentax was never meant for this type of work, it is my lunar and solar camera, but not being able to set things up as I like I have made do with the setup.
very much unguided, no alignment except for aiming for a tree to the south, and heaps of drift in very short exposures, but what the hell, I had a go.

and the winning shots are
the moon
Sirius