(1). Some experts tell me that Laudenbach's paper is incomplete and contains gaps. (2). The result you seek can be deduced in the following papers by Lizhen Qin (disclaimer: he was my student): *On moduli spaces and CW structures arising from Morse theory on Hilbert manifolds.* J. Topol. Anal. 2 (2010), no. 4, 469–526 *An application of topological equivalence to Morse theory.* arXiv:1102.2838