Here is the image I used for reference:
(Right click -> view image for high res)
In this image, the best reference for size would seem to be the cyclotrons on the packs, which we know to be 9". And here they are roughly 100 pixels wide. This makes it easy to calculate any length in the image. Simply multiply 9" by say .40 if a particular object is 40 pixels wide, and you'll have your answer.
Using this method, I've come to the conclusion that the large tank is not 10" in diameter as the community plans state, but rather 9", as in Slimer's plans.
In addition, while Slimer's plans indicate the two side tanks are 3" in diameter, and the community plans indicate they're more like 5.75" and 4.25", the sizes I'm getting are closer to 4.5" and 3.5" wide.
The brown sphere btw, if my measurements are correct, is around 6.25", which again is different from the community plans.
So what are your thoughts? Has anyone come up with a more accurate set of plans yet? Or do you have some proof that the large tank really is 10" like the community plans state? I don't see how it could be.