Well, just got this one and thought it was worth posting what is in the box. Kit is molded in two colors with 4 little sprues for each Maus, three for the Ratte, plus upper/lower hulls. Everything is cleanly molded with a fair amount of detail considering this is 1/144 scale. The hull is about 10" long and, fortunately, all the road wheels are connected together rather than being separate pieces. Same for the treads. There are PE railings and a small set of decals. instructions are typical exploded views and pretty simple. This one will go along with my 1/144 Leopold, Karl, and Dora to give some sense of scale. Here's what's in the box:

That's really great detail for the scale! I know nobody will ever produce a 1/35 scale Ratte. I might get this kit! It looks pretty cool!

The main turret was to have been a Scharnhorst/Gneisenau - type, with the center gun removed and the aperture plated over. The resulting space was to be used for ammo stowage. Is there simulated plating on the kit turret? If not, it can be easily added.

How much did the kit cost + shipping, if applicable? (Ball-park figure) The model is about the size (or bigger) than most 1/35 tanks, but with a lot less parts. Is it, in your opinion, worth it?

Cost with shipping was about $55. I wanted it to go with my other models at that scale and it is the only one available. It will also be a pretty quick build. Definitely a unique addition to a collection.
I am out of town on business but will check on the plating when I get back in a couple days.