Ah. That looks much better.
Ah, the bottom is open. That’s a whole 'nother ball of wax, you can totally do that if the bevel doesn’t have to be perfect. I thought it was a backed depression. A dremel tool and a steady hand (or preferably some sort of jig) should do the trick.
Yeah, the angles of the bevel are unimportant, in fact, smooth might even be desireable from a noise standpoint. What matters is the size of the opening on the bottom, and the top surface. What happens in between doesn’t need to be perfectly angular like that.
I’ve got a local buddy who has access to a Makerbot and he said he’d give it a go. Can’t wait to see what that result is.
Otherwise, I’ll probably cut a relief out of foam and try to melt some ABS over it.