Don't know a particular plasterer in this area, but if you try Hendry & Son at Foulsham Tel: 01362 683249 they may be able to help. They supply that sort of material and I know that they come out this way as we've had them do work for us. If not they may know of someone local.
Have you tried mybuilder.com? http://www.mybuilder.com/ I've used them before and got a good job done at a good price. If the workmen are any good then customers will have given positive (or negative) feedback for all to read.
I would definitely recommend Adam Williams from Thurton. Along with his team he did our whole house, inside and outside rendering, they did an excellent job, it took them about 8 weeks solid i think. I didn't have Lyme, but I know he does do it because we spoke about it. His number 07733 107339.