Corrected grain leather has a thick opaque topcoat / paint-like layer that's been used after heavy buffing of the grain surface to cover up obvious imperfections.
This topcoat gives a very artificial, plastic-like sheen / appearance.
On close observation, you will also note that none of the typical surface features of full grain leather (ie, normal hide texture, hair follicle openings, even vein shadows) will be seen. The surface is quite flat and feature-less.
I'm sorry as I am not familiar enough with Loake's offerings to know which lines are CG and which are FG, and based on superficial observations of your photos, I can't be absolutely certain.
I'm sure though, that the 1880 line is FG.