I have a suggestion,
@MichaelW:
Don't bother with the basic DIY shells of (sometimes) questionable quality from eekBay/TaoBowl/AmplifiedFarts/Alleybuhbuh/DiminutiveB'ar etc — unless you like monkeying with the mechanical aspect of things. Then by all means go for it.
If you want to just pop a board into something physically ready to work, I recommend
catching a sale at TinySynthyCubBear for
a unit that's damn near on par (if not right there) with commercial shells from Dunlop etc.
Foreground, in cling-film the former-indicated DIY shell; above and beyond it are 3 of the latter-described working wah-shells: