On the VUK on the mini-playfield make sure the ball popper has all 4 notches still on it. If one is broken off, the ball will shoot up crooked, and not cleanly through the wireform.
http://www.marcospecialties.com/pinball-parts/03-8561
The lost mine you can do a couple of things. Try to bend the scoop so the ball comes out at a different angle or what I had better success with is changing the coil to a lower value with less power. It "should" pop out over to the right flipper. At least it's nice if it does it that way, lol.
Found that here. www.flippers.be/basics/101_adjust_pinball.html
Also great advice to just rebuild both mechanisms.