These locomotives were released by "Hobbycraft Canada", which I've been told specializes in Canadian livery locomotive releases. They previously released locomotives under the "Life-Like Canada" banner, but after Life-Like was acquired by Walthers they changed their name to "True Line Trains". Atlas acquired the tooling for these models in 2019, so expect a re-issue from them at some point.
These locomotives are basically the Chinese-made Atlas RS-11 model (just with a couple of minor variations in shell detailing). The mechanism sports all the features one normally associates with "modern" Atlas diesels - IE, split-frame / all-metal chassis, 5-pole / skew-wound "scale speed" motor, dual flywheels, low-friction drive, bi-directional "white" LED lighting, all-wheel drive and pickup (no traction tires), blackened / low-profile wheels, shell-mounted Accumate couplers, all-plastic gearing, etc. The chassis is fully DCC-Ready (and, in fact, available with factory-installed decoder).
Performance on these models is perfect in every way - smooth, quiet, flawless pickup and throttle response, exceptional pulling power, etc.
The RS-10 and RS-18 models are identical (with the paint scheme basically determining the corresponding designation). And as alluded to above, the differences between these shells and regular Atlas RS-11 shells are extremely minor (basically boiling down to a few extra little indeterminate bumps and blobs here and there).
Shell removal is very simple - just take hold of the shell with one hand and the fuel tank with the other. Then just wiggle the shell up and off.