This is absolutely outstanding ! The level of detail you achieve is humbling.

My two cents : in sepia, your mountain ridges pop out a bit too much in close view (their line width seems a bit above the average of the rest of the map). It's most certainly not a problem but you might want to check how it would look like with a slightly lighter color (to make them a wee bit more discreet). Just a suggestion that might be complete crap