I find it annoying how people are saying that games are not realistic, therefore realism is unimportant. The arguments, too; ebony being a wood and quicksilver being liquid. Did you know that ebony can also mean black? And I for one have almost never seen the name quicksilver used as a liquid, so for the sake of fantasy, lets just let them mean whatever the devs want them to mean.
My own solution to the dragon weapons would be to add dragon blood as a loot from dead dragons. You could fuse the blood with some other metal, like daedra hearts can. Then, dragon bones would be used instead of leather strips. The bow could just be bone.