My Basilisk was built years ago, with an Earthshaker platform that slides out. That forethought allowed me to add another platform later.
Later is now.
For this I used an Earthshaker breach and chamber turned backwards and trimmed down, the armature from the tank plow, also trimmed and shaped. I built a pivot on the armature itself and then used a Lego hinge shaved and placed to allow the Medusa to aim directly and indirectly through two points of articulation. The motive assembly for the gun is an extra Tau ion cannon or somesuch I had lying around.
Finally, I used various bits from the bits box to detail. The muzzle is a marker cap. Not shown is the breach door or bearing races installed.
The breach fits used 9mm casings from the last time I was at the range. At some point I’ll build some Medusa rounds and a crew for loading the Medusa.
Overall, I’m happy with it, given the time I put in. I’ll prime and paint it at some point this week but priority number one is the 5th squad, which is well underway.