Hey Rowland,
Been a while - hope you're well
The streaking is somewhat hard to see with all the JPEG artifacts, could you maybe post a 1:1 crop or host the full image somewhere?
Since you have ST, download the latest 1.1 Beta and try the Chroma Noise Filter in the Develop module. For people with Photoshop, the technique discussed
here will do the same.
It's hard to judge the streaks from the attached JPEG, but if they're horizontal or vertical (most likely due to read noise), try using the (experimental) Band module in ST 1.1 beta. For people with Photoshop, Noel Carboni's Astronomy Tools Action Set does something similar (but it's not adaptive). For best results try using it while the data is still linear (unstretched).
Cheers,