Thank you to those who gave me advice on this.
I called NLM and the springs arrived next day, excellent service. I couldn't find the Hagon number on the box, so buying through NLM must be the best way to go.
With the new springs, the original sleeves/guides are redundant, as they don't fit, and the spacers are not used. Together with 10W fork oil, the handling is improved immensely.