The FW is a later model, not the original one. -> http://camera-wiki.org/wiki/Rolleiflex_4.0_FW
It should not have the delamination issues mentioned.
The mid- to late fifties saw Zeiss (and perhaps other manufacturers too) trying new ways of cementing lens elements (UV curable glue?) which in time has proved unreliable. I have seen Planars (both in Hasselblad and Rollei) having delamination issues. The Planars have curved and quite thin elements, which means that they might crack should one try to separate and reglue the optics.
I can't vouch for every specimen out there, of course, and quite possibly there are a great amount of pristine Planars still hanging around from that time span.