Saw this endoscope holder for the MK2, geeked out and ordered a scope of my own. The original wasn't even close to a good match, and I don't have the skills yet to modify an STL file for what I needed, so I crafted my own in OpenSCAD. Took a few hours to get the layout right, and I am sure there are far easier ways to script it. The first print of my design was off by .5mm diameter for the holder, and 5mm for the fan area. Other than those, not bad for from scratch.
I printed with a 20 line brim, as the original actually left the bed 3/4 near the top, leaving the print head streaming filament in mid-air.
This model is the finished version. Video of a test print is at https://youtu.be/xn_h_34N5J4