An 80" bow and 29" draw won't won't be benefited by adding recurves. The extra tip weight of the recurves(thicker than straight tips) will detract from the bows performance. To get the full potential from an 80" recurve you'd would have to pull it 38" or more. Also, horn weighs more than wood so you are adding more tip weight with horn recurves.
If you are intent on building a war bow, go to our "War Bow" section. Those guys know the scoop on war bows and can set you on the right path for you to take.