Arvay
Obscurant
Very lucky - well done. I have one of these with a similar problem. If the fungus is bad enough it secretes an acid which etches into the glass, leaving a haze that cannot be easily polished off. I sent mine to Essex (in USA), and it came back with scratches but the etching stubbornly in place. I've recently discovered Longman Optical in Tasmania, and sent them the element to see if they can tackle it. I'll let you know the outcome. The other person known to do this work is Focal Point / John Van Stelton.
Thanks, ChrisN!
Any news would be appreciated.