Dan- I don't know if your part is heavier than you want. It looks like there is excess resin in the layup. I have a rocket pod I made for my F-94C that is 13" long x 1 3/4" dia. Finished weight is 1 3/4oz. Lay up is first layer 3.2oz cloth, second is 5.0oz cloth and 3rd layer is 3.2oz. cloth. On my tip tanks I did 3.2oz on all three layers and they are strong enough. I am not criticizing, just saying what worked for me.
Other mold work I did for the F-94C is on this web page.
http://www.sidgates.us/HOBBIES/F-94C/F94C%20PROJECT.htm