Posting this here in case anyone is interested...
Whilst I don't think this is quite the same as a professional's touch, this is an interesting approach on getting that PVD look. The results and hardiness of the finish look pretty good.
http://www.indohomage.com/viewtopic.php?f=17&t=4312
I have a vintage Heuer and Tag where the cost of restoring the PVD will be several times more than what I paid for the watches.
If I had all the tools required I'd be tempted to use them as project watches and give this a go.