I picked up a used peerless 700 as my first rebuild project. It's a knock off "Topac" sold by EC. The previous owner did tell me he changed gears while the mower was moving. The problem is it won't go in gear IF you happen to get it in gear it pops right out. I've read the sticky about building a 700 several times. It mentions the gears must have sharp corners. Never having torn one down what should I be looking for? Shifting fork problems? Rounded gears? With it being originally sold by EC I'm hoping it should be race prepped internally. Let me know what you guys think, thanks