Hi Eddie.

I don't know anything specific about the second watch, but it does conform to Heuer's 6 digit numbering schema:

http://www.chronocentric.com/forums/heuer/index.cgi?page=1;md=read;id=42442

It does re-use the model code for a later Kentucky, but that's not the only time that happens in that model code list and the watch does look like it would pre-date the Kentucky. We see from the PVD Monaco that Heuer was looking at this 6 digit schema even for its own watches quite early on, but rejected it for some time in favour of the 5 digit version - it's possible they adopted it earlier on watches they were making for third parties.

Now, none of this confirms as such that it was made by Heuer for Zodiac, but it would be quite a coincidence in case references if they didn't.

Mark