Milo,
I was wondering why it has an MW-50 sticker myself. At the house I have numerous color pictures that show very clear close ups of the MW50 sticker. It is located on the right side and not the left as would the C3 auxillery tank warning sticker.
The 115liter tank was not much bigger than a propane barbecue tank. It was bigger but not as much as you would think.
Additionally, according to some of the documentation, the much smaller 85 liter tank was used for GM-1, MW, and EW boost systems.
Crumpp