I'm shopping a "Bowling Queen" and I'm amazed at how peened the front edge of the runway bridge is. It's like the ball is hopping up in the runway (AKA "shooter lane") and routinely smashing into the metal bridge near the top. I had to grind the edge off on my bench grinder and will re-install it the other way around. This can't be good for the surface of the ball. I just don't know how this happens!
BTW, this, and most other games I've acquired lately was high-tapped. This particular one was in home use for the last thirty years. I suspect it's been high-tapped for much of that time. I tore down the 0-9 unit, and found that it had quite a bit of wear on the ratchet wheel, and the coil stop was heavily peened and the stud was broken off. This is why I'm such a detractor of needlessly high-tapping games. If you want faster game play, go ahead and install hot coils, bridge rectifiers or whatever. But don't needless stress non-gameplay components by jacking up the voltage on them! They WILL wear faster!