fire surround

Hi Everyone, We have bought a couple of fire surrounds and it seems that the inner legs don't fully reach the wall despite all the other parts of the surround being flush to the wall (attached pictures). Anyone know why this is or how to make this look half decent? I don't even know where to...

Just moved into a new house with a gas fire. The stone on the fire place seems decent but the fire surround is a really cheap looking stone effect resin we think. Does anyone know what our chances are of removing it ourselves without destroying the wall or stone behind? Added pics to help...