Yeah, it's all on my end - been running around like a headless chicken the last couple days. In this case, that variant file IS in on my end so I'm gonna put this down to me basically never using dropbox and not checking if it actually updated properly on there.
Sorry 'bout that. I've updated the link in the OP, with the download being so small there's not much point in just giving you the missing file

Just editing this because I don't wanna just bump it constantly with all the screwups over the last couple days, but current plan for the next addition?
A capital ship made by a madman. The design called for more speed than a conquest, more frontal firepower and armour than an onslaught, and a paragon's fortress shield. Obviously, to any sane man, this is impossible. But pirates aren't the sanest bunch, and the ATX project takes commissions from all sources - especially when the required parts are provided by the client.

Note: Sprite made by Levik, I just cleaned it up a little.
Being primarily made from salvage recovered from a large scale Hegemony-Diktat battle, the main hull is an onslaught, though large parts of the exterior have been replaced due to extensive battle damage. The woefully inadequate engines of the onslaught have been supplemented with a partially complete set from an eagle, along with two smaller maneuvering engines from a brawler. As the central spike of the onslaught was unrecoverable, it was decided to instead construct a new one, taking the frame from a second onslaught, stripping it completely, then cramming the sole functional TPC on the front and covering it with a welded mishmash of mostly armour. The rear section contains parts clearly salvaged from a paragon - though where these were acquired is unknown, and due to material constraints, the planned large rear turret mounts were removed to allow for much needed additional flux dissipation.
The Siegebreaker does indeed boast more frontal firepower, more speed, and more defensive toughness than perhaps any capital ship in the sector, but it certainly cannot fulfill that role itself - with minimal firepower in any other direction and an almost complete inability to turn, the ship cannot function in a fleet based battle without heavy support. But against a stationary target, such as a battlestation or particularly slow capital ship, it's sheer slugging potential is unmatched.