Thanks, everyone.
Well, the vet said he's put on 350g of weight, his heart sounds fine, his temperature is fine - he 'loves' that bit, having a thermometer suck up his jacksie - and the skin around the tube is healing - last time she said it was becoming necrotic where the sutures were so this is good. The main issue is his feeding. While it's good that he's eating all that raw meat it's not a fully balanced diet for a cat and he needs to try to get back to catfood; whichever sort he'll eat, really. I have some samples to try him on but the medicated stuff from the vets is like a paté which he's never liked - unless it's a good duck paté with jelly and cranberry bits we got for ourselves of course, he makes an exception there. But the catfood like that he just won't eat, he likes jelly and lumps. I'll keep feeding him the meat but try and get him to eat other stuff however I can. Perhaps meat, pasta and veggies would suit? He'd like that, anyway.
If he can't feed himself properly with his nose/palette condition though we will have to consider operating but that's very much a last ditch thing.
The RVC consultant is now away for a couple of weeks so everything's on hold till then when we will see what state he's in and think about a route forward.
Fingers crossed for the next couple of weeks anyway where he must just build up his strength and put on loads of weight!