My 80 Atlas (unfinished) is approx. 57 1/4" from transom to tip of sponson. I had a friend make a plug, mold, and first Part cowl from epoxy glass. It is super-light, and PERFECT. It sounds like my length # is longer than yours, and thus my scale may be 1/5 th scale -vs- your 1/6th scale??
The good news is that a slightly bigger cowl may help cover the Gas Motor. I will take pictures of the cowl and send them to you if you send me a PM.
David Jensen
This is a scratch build for fun, and as inexpensive as i can. I just mounted the engine it's a little high but i did not want to cut into the deck so i will live with it. The cowling is going to be a challenge any ideas would be helpful. I'm trying to keep it as close to the 1980 boat as i can. I have a wrap to center header on order.