There FAS-STONE #7 is some awesome stuff! Though surely too weighty for a trasom...great for fixing holes big and small, tappable and sets up with a mirror shine if you treat it right (just put some soap and water in a bowl and get a finger or hand wet and smooth over. They are super informative, if you haven't called them yet, that would be my first call.
http://www.fascoepoxies.com/products.html