Thank you Bluto! My apologies for the delay, I had notifications turned off.
For anyone else reading this post…
The Ultimate Introductory Guide has been updated 8/28/2019 to confirm the ulozto links are dead.
Harmy has also confirmed this and is looking for an alternate solution. For the moment, usenet is the only confirmed location for mkv. Details available in the Ultimate Introductory Guide, Section 5
Thank you for the help!