This is a remix of Grégoire Saunier Prusa i3 Bear Upgrade Z-top https://www.thingiverse.com/thing:2808408
I basically just extended the top portion so it would also serve as a Z-cover. The cover part just floats so it doesn't change how the original part works; it just makes a nice finished look IMHO.
UPDATE 4/7/20: I trimmed the bottom of the extended cap part by .5mm to avoid causing any unintentional axis skew. Thanks to Grégoire for the suggestion.
UPDATE 4/8/20: As requested, I added a version for the Original MK2/3. Just for fun.
The author hasn't provided the model origin yet.