I don't believe there is such thing as an 11mil crank or cylinders out there..............It's eith a 10mil, 12mil, or simply BS.
DASA made the T-Rex cylinders and licensed them out to a few folks such FMF back in the day. Parts can sometimes be hard to get such as head hardware and sleeves. However, DASA still has all the stuff.
IMO the T-Rex is a dated cylinder design and a more current CP (Cheetah, Cub, etc.) or Twister can be had for the same money.