Well done!
Increase your image scale, if you can get the focal length up to 5000mm then there is much greater separation and it should split readily with your camera on a night of reasonable seeing. Visually, its a target for those nights with superb seeing when your image holds strong at 3-400x
I've attached a similar shot I took some time back and you can see how that extra FL helps it pop.
Your capture technique is great
