Follows on from:
I used M101 image from a previous night to create sky background image to subtract.
I created 2nd layer and slightly shifted it to make starts more round in shape.
I used curves to bring out data.
I used clone tool to clone out black spots that appeared in image after processing with other methods above.
I used Ian’s noise reduction in G’MIC plug-in for GIMP.
……Uncertain whether I prefer this image to previous versions!
Images below show different amounts of above processing: