Back mounted thermal cannon

Ever since GW released the Imperial Knight Kit I have been a bit upset about the lack of build options with the model. Most other kits nowadays have  multiple weapons set ups etc. The knight kit only has two weapon options. FW is cranking out some nice alternate builds but so far you cant buy the weapons separately so that is not an option at the moment. When building the Knight I have, I decided to build it with the rapid firing battle cannon on the arm and not to magnetizing it, as I have seen many others do. This left me with some spare parts and as I am thinking about a new Knight build I wanted to test if I could build a back/shoulder mounted Thermal cannon from the parts left over. This is just a quick build as it is more of a test than a sharp version. I painted it to match the knight I have and mounted it in the hole behind the driver compartment. It looks a bit bigger on the pictures than what it really is due to perspective but I think it looks nice. I know that it is not legal in game termes but as it is removable it is not a big deal. I am not really sure this Knight will have it mounted like this at all. It might get transferred to some other model later on. We will see...