Prusa Multi Material (MM) brackets for overhead filament spool feed i3 MK2s

Brackets + pulleys to allow overhead filament spool feeds (eg from here: https://www.thingiverse.com/thing:1332025) to be used with the Prusa MM kit (which expects the spools to be behind the printer).

These parts use the bearings and aluminium tubes supplied with the MM kit, intended for the spool holder assembly.
You will need to print a pair of brackets and 2 pulleys for dual material and 2 pairs and 4 pulleys for quad material MM printers.

Holes in brackets for the filament to pass th