lookin good! You could always speed it up with this kit. It rusts anything.
http://www.imperial-modellbau.de/shop/index2.htm
Or you can purchase the original method and kitmade byModern Masters Metal effects Iron paint and rust activator.
http://www.thehardwarecity.com/getProducts.html%3bjsessionid=3E87585529D30583DFCB 65518A121272?vendorName=Modern+Masters+Inc
ModernMasters Inc.
http://www.modernmastersinc.com/products.aspx?pl=ME
This is a true weathering kit that causes real rust. I used these for a previous studio sculpture years ago that required heavy aging. Really easy to use and the results are perfect.