As a Gundam enthusiast myself, I'd love to help... unfortunately, I don't know why you're posting this on TFW2005, nor do I know what "metal fittings" are.
Because many Transformers collectors also collect Gundam's. Having been on the site as long as you have I'm surprised you don't know that. By 'Metal Fitting's' I mean like after market thrusters or Machine Gun muzzles....