This seemed like a nice small addition tbh. It wasn't too hard to model either
This is the 120deg Plateau fountain link:
and this is the plateau cap link:
(I wasn't sure which model to remix so I just chose this one :) )
First (and probably last) edit: There was a small flaw in the big piece that I didn't notice when printing 'cause it fit mine, but two users had problems with it, so fixes ensued.
The author remixed this model.
Made a cap for a remix of it