This turned out to be a leaner than average but not super skinny boot. The midcalf measurement is decent at 13.75" in size 7 1/2. The top is 14.75, and the ankle is 11 inches around.
The price as of early May is terrific, so if you've got 13+ inch calves or don't mind a bit of gap, this may be a good option.
Calf slimness: ***/5
Find it at:
?? (Sorry folks, as of mid October 2015 this one seems to have completely vanished. Any spottings, please share...)
January 2018 update:
Like more bling with your riding boots? Hunt for the metallic-buckled Vaneli Realyna, which lists a 13" calf circumference.