Hmmm, why do you want to copy a production kevlar boat? You might save some weight, but you've already got the boat. I have a QCC Q400 kevlar boat that my girlfriend and I like so much I purchased the plans for it as the Caspian Sea and built a cedar strip version of it because I had the time and did NOT have the cash for another Q400. We wanted two in this case. They handle much the same, the cedar-strip boat is about 6 lbs. lighter than the kevlar and has a finer bow entry.
Why not call the designer and offer to buy the offsets for $45-50, explaining that you want to build a one-off?