[linstar88 (Linda and Guy)]

Hi Col,
Mate that looks like mould/fungas that's grown on your optics, most likely on the inside. It forms after having a little moisture rest on the optics & if it's not cleaned off fast enough, this horrible mould/fungas grows on the optics (as seen in your pics).
It's an optics coatings killer! Get it (professionally) removed asap & pray it has not been there long enough to have damaged your coatings.
I lost an old TV type 1 7mm naglar to this stuff, managed to save a TV type 1 40mm plossl acting fast ( I had to send my EP's back to TV in the USA to be properly cleaned). Damn eBay purchases are dangerous.
Seriously hope that cleans up for you Col, fingers crossed.
Regards
Guy