A canonical transformation method originally proposed by Munn and Silbey is used to partially diagonalize a model Hamiltonian which incorporates both local and nonlocal exciton-phonon coupling. At the heart of the method is a secular elimination principle which poses a difficult self-consistency problem. A limited form of this self-consistency problem was solved in an approximate fashion by primarily analytical methods in the original work of Munn and Silbey. We take a numerical approach, solving the general self-consistency problem to desired accuracy. Among the differences between our findings and those of the original work are polaron binding energies much larger and Debye-Waller factors much smaller than originally anticipated