19 APRIL 2015 UPDATE:
The thumbwheel/pushwheel for this order should be KM1 size. Thanks to middelweerd for pointing out the possible trap.
The case for my Thumbwheel Temp Mod for Up printers and so far as I know the original one :). Details on making the mod itself are NOW attached as a PDF. Sketchup file included to tweak for your preferred fitting.
Last photo shows two mods fitted at once - this case is designed to front mount - modify the Sketchup file for your own mounting system. You can see I side mount mine with a slightly different design. This is so it pops out of my custom enclosure to set it without removing the lid and letting too much heat out.
The mod is placed into the outer before the slide is slipped in to lock it all in place.