You can get the smooth surface finish by doing a
little hand sanding.
You could also paint the surface to get a good color match to your
existing switches as well.
I think painint htem is a bad idea, in that the paint will wear off
(think of how much use front panel toggles get). Is it possible to get
the raw plastic for such pritners in different colours?
Also, how strong are 3D pritned parts comapred to injection-moulded
ones?The original ones do break so if the replacements are significantly
weaker, they're not goign to last.
-tony