The "Upper to Lower" ramp on my WH20 (leads from the mini pf to the right inlane) has a slight lip where it meets the mini pf. A few odd things: 1) Pretty sure this is an original ramp, since I bought the game in the late 90's when such things were still widely available. 2) It seems to be slightly worse in the middle, though the underside seems to be flush with the wood. 3) Hard to see in the pics, but the screws sit at an angle, and due to this the front edge of that foreground screw is slightly elevated above the ramp, adding another obstacle for the ball to trip on. Maybe 1.0mm of ramp, and another 1.5mm of screw head sticking up at the worst point.
I'd like to make this edge (more) flush, but can't think of a great way of handling it. Shaving the bottom side of the ramp seems difficult, with no reference for "flat". Shaving the top side seems like it would likely leave ugly results exposed. And what to shave it with, anyway? A Dremel seems hard to freehand.
In terms of getting clean results, shaving the wood with a router seems like the best bet... but talk about nerve wracking! Sanding the underside of the ramp seems like the least violent, but again, difficult to be precise & probably won't look great.
Anyone else successfully dealt with this issue?
btw - in response to the obvious question, "Is it a huge problem?": Unfortunately, I don't know. The game's been in storage for years, and I'm just now refurbishing it - it's in pieces on my work table right now. I know I'll probably have to put it all back together, and then play it a bunch before attempting anything. But I'm still interested in the answer to this question.