Actually there was no rake. I was the technical rep for Zipp from '93 to '96. Kinesis made the fork to our specs and that was no rake, in the blade or through the fork tips. We wanted a straight line from the steerer tube all the way down to the front axle. The desire was to create a larger amound of trail allowing more stability while on aerobars.
We worked with Wound Up and they are probably one of the most talented carbon folks out there. Unfortunately the smallest amount of rake was 39mm and I believe that is the same today. Pretty expensive too. I checked out Alpha Q and have run into the same problem. Kinesis created the fork for us, but of course the production stopped when the bikes stopped being produced. I was hoping some frame builder could enlighten me to a source since I've been out of the business for some time.
There is a perception that less rake means more instability when in fact it is more stable. We used to test this by turning around a standard 43mm rake fork. If you had downtube clearance the bike would steer straight forever!
I did call Zipp and they were checking in the "back room" to see if anything was hanging around in the dust. No luck so far.
Sorry to correct you Dave but believe it or not there was one out there at one time. I was hoping that Zipp wasn't the only one using it.