The use of the "Rancher" designation may have been a bit "spotty", meaning it may have varied with time and market, but according to the IPLs the regular 55 came with a decomp valve in the cylinder and the Rancher not at that time.
Also, the source that told me that 967 05 27 00 meant Rancher may have been off
Pictures of the cylinder, including numbers and letters on it would be helpful.