I understand that Tracy used the proceeds of his sale of Pharoah, Rahasia, and Vampyr/Ravenloft to relocate to Lake Geneva and accept a job at TSR. This much I learned from Tracy directly. The exact date I do not know for sure. But I could reasonably discern that it precedes the printing of Pharoah circa 1982 by a short amount of time.

Now, he claims to have written some of or most of his Daystar West adventures starting around 1978. I figure this includes Vampyr as he mentions it was written and play-tested a full 5 years before it was published, for the first time, by TSR.

The Eye of the Dragon was in production before an expensive mistake in the printing of the cover 'encouraged' the Hickmans to seek employment at TSR, as luck would have it, included the sale of their previous efforts along with offer of employment.

Actually here is the thread:

viewtopic.php?t=1864&highlight=hickman

It was started by a2jeff March of 2005.  Here is Tracy's message board:

http://p083.ezboard.com/bthebronzecanticlesvillage

The bad news is that it doesn;t appear to have been very active and the last post on it dates vback to June 2. Still it might be worth a shot.