Just to finish this off, I did end up putting that silver insulation stuff all round areas that were getting hot. Anyway I noticed in time the stove wasn't getting as hot, I'e heat coming up from the sides where the Morso outer protective plate is. And in time it all went back to normal. I still don't know the answer, maybe my sweeping the chimney a couple of times better than last year, maybe replacing the front glass.
i will have to re assess next year, I did not try sweeping the chimney again this year, but Winter has been mild, temperature wise.
Anywayas an aside , this year I have been using a new coal, and have used it for last four months, it has made me rethink my ideas of changing to a diesel burner.
I use "glow" briquettes, my fire has been on constantly, I have to empty the ash pan once a week, last year it was once a day, or fire choked itself and went out. Brilliant stuff, it's about £12 a bag, I mentioned same to someone else who used it, but did not have a squirrel, he did not find it as good, so all I I can say I have found it great in our set up.