I made this spout because I didn't want to drive to my hardware store and buy one. Fits every one gallon paint can I have so far, so I suspect it will fit yours.
I printed this with support which pops out really easy.
Easy to press and tap on to the can, and easy to pry off.
Enjoy and improve if you'ld like.
PaintCanSpout.stl | 97.2KB |