Re: fitting - comprehensive fitting instructions come with the mesh. They are easy to fit apparently, but wont pop out easily!!
The mesh is high grade stainless steel, welded, shaped and zinc plated so you wouldnt be able to get the mesh from them and do it yourself as it is quite a prolonged, thorough process, hence the quality
I updated the first post on the thread with contact details. They have a technical department that can answer your queries.
I would suggest that as soon as someone fits the mesh, they post a 'How to' guide here with pics.
Thanks
Linda