http://en.wikipedia.org/wiki/Landkreuzer_P._1000_Ratte
http://en.wikipedia.org/wiki/Landkreuzer_P._1500_Monster

Both the Ratte and the Monster were proposed, but never built by Germany in World War II. But now, 70+ years later, the Ratte has been built..........in a 1/144 scale model by Takom! Hooray!
http://www.1999.co.jp/eng/10308781

Armor modelers can now rejoice at finally having a scale model of this far out fantastic what if subject!

But what about the P1500 Monster? Will there ever be a kit of that? And if not, then how to scratchbuild one? What would it look like? I've already bought a Takom kit so I can build the Ratte. And I've bought one of the following too so I can eventually build a 1/144 scale P1500 Monster to go along with the 1/144 Ratte:
http://www.amazon.com/Scale-WWII-German-Dora-Railway/dp/B000P92YWI

The P1500 was designed to use the same calibre of gun as that of the Dora railway gun.
http://en.wikipedia.org/wiki/Schwerer_Gustav
http://www.the-blueprints.com/blueprints-depot/trains/trains-0-9/80cmke-dora-railway-siege-gun.png

But the biggest hurdle is that of deciding what would the gun be housed on/transported on? A few sketches/concepts I've found are the following. If a real P1500 were to have been built (or even a model), then what type of transport chassis would it have?
Sample A - http://upload.wikimedia.org/wikipedia/commons/e/ef/P1500macedon.jpg
http://i730.photobucket.com/albums/ww304/StugE100/Monster1.jpg

Sample B - http://s2.blomedia.pl/gadzetomania.pl/images/2012/10/c10-312959.jpg

Sample C - http://kampfgruppe144.blogspot.com/2012/06/1144-landkreuzer-p1500-monster-matuo.html
https://s-media-cache-ak0.pinimg.com/originals/17/fa/b4/17fab4eea5d952ff19f43153150bad44.jpg

I'm not keen on Sample A. I could use B, but am not sure what type of model tank or other vehicle hull/chassis to use to mount the gun on. Sample C is nice as it shows the gun being supported/transported by two P1000 Rattes.

Hmmmm. No replies yet. Well, for those who don't understand this thread, I will be building the 1/144 scale Takom P1000 Ratte. And then after that, I want to build a 1/144 scale P1500 Monster by using the gun and other parts from a 1/144 German World War II "Dora" railway gun model kit. But in order to build the P1500, I'm not sure what type or scale of tank hull/chassis to modify and put the gun on, etc.
Samples B and C in my earlier post are the only two decent configurations. Which would be better to build/use?