Hi - thanks for your reply.  I've been thinking along the same lines though unsure where I'd purchase 'acoustic foam' from.  I've made 'dead cats' before for some of my active monitoring mics and that material is not too difficult to source but the only acoustic foam I've come across is the type for deadening sound in studio etc. - the exact opposite of what I want!!  The search continues ....!

Brilliant - thank you.!  Great idea about the screen too - I'm replacing some of them monthly so may try that myself.  Have you found any issues with the mesh generating any tones with wind?