David,
I cleaned the ray-skin with a toothbrush as you suggested.
I started with just dampening it then tried some dilute ispropol alcohol.
Complete success! Looks fantastic now.
Thanks mate
The stuff is suprisingly sturdy!
I've had the blade oiled in readiness for cleaning the minor rust dust and small problem areas by the hilt.
If anyone has any suggestions for cleaning the etched blade then I'm all ears?
Best
Gene