I have acquired a very lovely Prima 16CS anamorphic lens which is bedevilled with fungus behind the front element. Has anyone taken one of these lenses apart to clean it? Anything to look out for?

Sometimes it is the Canada balsam holding the sandwiched lens elements together, not fungus. It may be only a cosmetic issue that is not blurring the projected image?

Hey Stuart. I hate to tell you this but if there is fungus on the interior elements of the lens itself then there has been moisture getting inside for awhile. Lenses are made of multiple elements and getting inside them is difficult at the best but neeeds to be done in a zero humidity enviroment with special tools. If the projected image is being affected then you may need to get a different lens since the repair means completely taking the lens apart which is several elements. Once the lens is comprimised with moisture it is pretty much gone.

The London Camera exchange here in Plymouth did tell me that they have a company in London that they send len's to if they can be dismantled for professional cleaning. They wouldn't tell me who they use,(they wanted to charge me there bit) but some older camera shops will still be able to do this.
When we bought our sankor 16D scope lens many years ago this one was also suffering quite badly with fungus. This one was dismantled by a good old photographic shop here in ebrington street in Plymouth for just £15. Unfortunately, this one is also closed. Be worth hunting specialist photographic camera repair shops Stuart. Hopefully there should be one in London I'd have thought