By Kevin Haas Four years ago, Rockford's historic Gunite manufacturing plant was at a crossroads. Owners had to decide whether to close, sell or fix the underperforming plant. Accuride CEO Rick Dauch, who had been recruited to lead Gunite's parent company in 2011, chose the latter. Today, after four years and $63 million in improvements, the plant is recognized as a model of manufacturing excellence.…