G'day Paul,
For an image that was taken without doing a PA & just by 'happenstance' it's a pretty good result & quite pleasing to the eye.
You should be very happy with the result...
Now, to be picky...
If you zoom right in you will see some trailing of your stars, this will be because of your PA but, I think you probably know that already...
Also, your focus seems just a little off (again, when zoomed in & being picky)... do you use a bhatinov mask for focus or are you just doing it by eye...? If not already using one, I definitely recommend a bhatinov mask for getting focus spot on...
If you've already got that covered, have a look at any denoising you might be using, either in camera or, in post processing as this can also have an effect on how sharp your image is as, I have learned recently myself...
To limit noise, look at every function your camera has turned on & turn off the unnecessary ones... things like in camera denoising, auto focus, face recognition, tracking and shoot in raw & only in raw... you will still get an image preview but, you avoid the whole in camera processing to a jpeg image which, along with all these other functions, generates heat which equals noise....
I use an EOS70d & I have turned off pretty much every function in the camera that is just not part of the necessary functions to capture astro data... I also use a dummy battery connected to either a mains supply or through a regulated dc output of my power distribution box.. this means, less heat in the form of battery & again, reduces noise...
I battle heat up here all the time with the absolute minimum temp in the dry being at it's best 13*C.... since I don't want to go down the cooled camera route, I just turn off everything in camera that I don't need... does it make a difference... yeah, a small one but, if that gets me some image quality improvement then, it's worth it...
Cheers
Carlton