Clear silicone adhesive works wonders here. Do not attempt to join the hood together at the seam and then install it as that can be messy and not always successful. Instead install the hood, dab some of the GE clear silicone cement under the hood and press it against the surface of the brake lever body so it bonds to it. You will have to either tape it or zip tie it in place till the adhesive dries but it works. The silicone cement is the same consistancy as the hood (if it is still supple as you say) and that stuff is strong yet when you want to remove it, a razor blade will allow you to scrape it away with little effort. Don't be over generous with the adhesive as that can lead to a messy situation. Just put enough to cover the mating surfaces and you should do fine.
Ray Homiski
Elizabeth, NJ USA