Print "_nosupport.stl" directly (already oriented correctly and centered)
or the old way (oriented sideways) with breakaway-support and with "_support.stl".
Print the body of the original extruder and assemble.
You can use Jag's quick release or a spring with 2 washers on the long pressure bolt/threaded rod.
Tested and works very well on a Thing-o-Martic as an MK6 replacement.
Print with lots of infill! (0.8 works well)
Parts are in INCHES (sorry, it's a derived design and the original was in inches).