I thought that all the round backed harps were made with plywood, but when inquiring about a curly maple Troub, a harp dealer told me that the round body was solid curly maple that was steamed to make it curve.
I happen to be in Paris just now and guess where I went today? Yep, Camac showroom! I asked the very same question of the representative and he indicated that all (as in all ) Camac harp soundboxes are made of beech wood and veneered most commonly with maple unless otherwise specified. When I wrote recently to L&H about an Ogden they told me the box is solid maple. I guess each harp designer/ builder has their own right way of wood working for the effects they want to produce. So many things to learn about production! As for me, still so new, I must take a leap of faith and choose what sounds good and works for my needs now.