Bulge/deformity in Dutch West stove

[CutsThroughKnots]

Has anyone seen something like this? The stove is well over 20 yrs old and will soon be replaced as I’ve bought a bigger one. Only just noticed the deformity at the top of the fire box. See photo, thanks for any thoughts.

 

[sand sock]

We had the large model and the back panel had cracked and we never figured it out. It was leaking smoke into the house, just so you could taste it. It only lasted maybe 7 years.

 

[CutsThroughKnots]

Mine is still sealed up tight, vents normally through the flue. Don’t know if I should risk installing it anywhere else, though. Might be finished.

 

[wrcho]

looks like flame deflector for the cat converter above it.
The back and side burn plates may also be cracked or broken too. Usually caused by overfiring the stove, hot enough to melt cast iron. The top
plate and others are replaceable. IF (as you indicated) the plates behind and
above are not cracked too.