Okay, at 63" you have plenty of length for a flatbow, of your regular design for a 25"draw. The 70" length could easily be made into English longbow(either stiff handled or bend through the handle". I have made excellent stiff handle longbows from yew(unbacked) 65" btwn nocks drawing 26", 1" wide 55-60lbs fine ringed yew. Go 1&1/8" wide if you want a 65lbr
The 70" length would allow you to make a 28-29" draw medieval style bow, that you could draw to the ear, if you so choose to.