Thanks guys for all the support!
I have just come back from the vet where Garry has put on 45g since last week...she weighed him twice just to make sure. I couldn't believe it either, he was just so frail looking last night that I thought that was it.
He really rallied today and has literally spent all his cage time 'picking' from the mixtures he has in there. At one point he was pawing at the hay and was trying to eat it...couldn't believe that either! The vet has filed his front teeth down again so it should now be easier for him to pick things up. We also have a couple of modified syringes (the ends have been cut off!) in order to make administering CC easier. It seems that G has decided he is going to fight this all the way. We'll spend this week working 150% on him and hopefully he will start to improve.
Debbie & Lucinda - I am going to work with Garry this week - syringing CC, puree and water into him. He seems to have a good appetite which helps as he is feeding himself from the mixture too. I have made a note of the Cat & Rabbit number just in case though and I will use it at the first sign of trouble.