Thanks for all the input guys. After much sucking of teeth I have decided to go with the original shape and add 4 inches to the top and bottom width. Not too worried about the angled cuts.......what else do I have to do with my time? The firewall will remain the dimensions as the plans. Have updated the web site with one photo showing the final shape.
Bought some syringes and ran some tests on volume vs weight when mixing. Have the figures here to decipher and will post the results shortly. -- Darren Crompton AUSTRALIA www.kr-2s.com