Thank you Brian and Douglas.
Douglas,
The process allows for some experimentation with process and image selection.
A link to a YouTube tutorial is here;
Simple steps,
Open image in Photoshop
Filters - Pixelate - Mezzotint - Medium Lines
Filters - Blur - Radial Blur - Amount = 100, type = zoom, quality = best
Repeat a few time if you want to smooth the blur more, don't if you want to retain some lines. The one above was a single blur.
Duplicate layer (any name you like)
Select original layer
Filters - Distort - Twirl - angle (80 or 100 works well)
Select new layer
Filters - Distort - Twirl - angle (-80 or -100 to mirror the previous step.
Select top layer
Select Blending options - blend mode = lighten, opacity at 100.
Et voila.