THOUGHTS ON "TONY'S CUSTOM UPPERS" UPPERS....he is at all major gun shows on the east coast and builds custom uppers. The flattops have a "fish like / key hole" marking on it (dont know what that is) but I am wondering if they are accurate and "good quality uppers with good barrels?....Any problems?....How about a M4 flat top upper and M4 barrell from Tony's?