I have noticed that the top plate of my stove (morso Lion) no longer sits flush on the body of the stove. The right hand side has lifted by a cm or so. I assume this is a bad sign.

I have done a bit of internet research and it would appear that it could be due to the baffle becoming warped or worn out.

Has anyone else experienced this and how much is it likely to cost me to sort it out?

I am trying to get hold of a professional to come and look and give me an assessment but in the meantime someone on here must have some knowledge on the topic!

Had the same thing a couple of times with my Morso Badger. Top plate seems to have shrunk but its the outer plate warped making the orifice larger. Think it cost about 70 quid to get new plates.
We used to use Blazers in the stove which are compressed wood about 3″ diameter by 12″ long. Made the living room like the inside of a nuclear reactor! I blame them for getting the stove too hot.

Thats good knowledge! Did your stove look like the top plate just needed to be put back on properly? Or like you just needed to shift it over a fraction of an inch to make it fit again?

I burn wood and some maxibrite style coal ovals so maybe they are to blame. Got someone coming to look later so hopefully I can get some idea of the cause and how to fix it!

Not sure what your layout looks like but our top plate sits at an angle on top of the side plates with a ‘leg’ on each side running front to back. The baffle plate then sits on top and within the legs. When the top plate warped the legs spread (ooeerrr!) So the baffle plate could fall through the legs so it was a balancing act until it just wouldnt stay anymore.
Hope you get sorted cos winters coming!