Looking at buying an older two pin Gen3 Glock 17C from someone in a neighboring state. The firearm was kept in great condition, seller is not the the original owner. He sent me a few pictures of it's current condition, and I saw something that caught my eye so I figured I'd reach out to you guys for help. As you can see in the pictures below, I noticed at the front slide rails, more-so the polymer behind them look to have a bit of chipping and a small crack or two. I've got 6 other Glocks, one Gen1, four Gen2's, and one Gen3; none of which have slide rails that look to be in that condition. All of my slide rails and "guides" look to be nice and smooth and in great shape. What I'm looking to find out is what would cause this, and would this be a deterrent from purchasing this firearm? I'm concerned for long term use, as a range toy this will likely be used and abused. Any help on the matter is greatly appreciated.