Have you tried LVMH? I recently sent my Pasadena off to them for help with bringing it back to life and found out that it is considered Vintage. Long story short it is now in Switzerland at Heuer and I have just gotten a list of items they can replace, including the crown. If you are unable to source one easily you might give the factory route a try. By the way, if you are in need of a new bracelet for it, that is something the factory does not have, much to my disappointment.

: Thanks, these photos are very helpful. This probably confirms that
: the crown on mine isn't original as clearly the crown should
: have the same PVD finish as the case and pushers. The crown on
: my watch seems to have a painted finish with either brass or a
: gold finish showing through, rather than a hint of steel where
: the PVD has worn on the edges. Additionally the crown on my
: watch has only 20 'knurls' which seems to be less than these,
: although, curiously the knurling on mine appears to be finer.
: It would seem that the crown on my watch was replaced at some time
: with one that is a good match in size and profile but it was
: painted over a gold coloured finish.
: Any help in finding a correct replacement for an otherwise fine
: watch would be much appreciated.