I guess that the most important things for getting a custom bike from Dean (or anyone else for that matter) is the guy that turns your fit measurements into a bike frame design and then the guy that takes that BikeCAD drawing and does the actual fabrication.
In talking with Yo not to long ago the Bike CAD guy is John Seigrist who has been with Dean for quite some time and who I think is still there. I think that John may have actually started Dean. Dean's main fabricator was a guy named Ari who may or may not still be there. It would be nice if someone can confirm this.