I'll throw my two cents in for kicks n giggles, n stir the pot up....because I know it can be done,although not easy by any means..even for someone with a fair share of bows under there belt...BUT......
#1...you first need a perfect, flawless,99% clean,100% straight piece of wood that will allow 2"+ of width easily...
#2... I know of two designs best for this...either a bend in the handle R/D with short shrap static recurves..or the other which is similar...a bend in the handle R/D molly curve...and if he likes a beefier handle then build it up with cork....both are a tall order to not only make,but to be executed by the bowyer is prob the toughest part..and have the bow be a durable long lasting bow that is also not set ridden...
GOOD LUCK!!!! I'd rather work at trying harder to convince him to make it longer IMO