Try starting with the watch itself, not just a watch case...
http://www.thingiverse.com/thing:1254
http://wiki.makerbot.com/makerbot-watch
> what are the board measurements?
Check the .brd file in EagleCAD.
> how is the thing powered?
CR2032 Li coin cell mounted on the back (look at the photographs of
the assembled watch on the above links).
> and how do you set the time? this is greatly apprechated
Depends on what firmware you are running. My watch is just running a
test pattern because I got it assembled then designed and printed a
case for it ( http://www.thingiverse.com/thing:2990 ) and I use it
more to show off a real object merged with a printed object than as an
actual watch. I know at least one version of timekeeping code has
been mentioned on this mailing list - check the archives for links.
-ethan