I haven't studied the Monaco that you are questioning, but we had a major discussion of the three-register, blue manual Monacos several months ago. Much of it, including the variations on the open and closed "4"s, is discussed in the following page. You can read it in the frame below, or click here to view this page in a new window.

: I want to know what the experts think of this
: auction on German Ebay for a (I think)
: 73633B Monaco.
: It looks to me like the seller has gone through
: a lot of trouble making this one look as
: authentic as possible with the box and
: warranty papers et all.

: The thing which (according to make) gives it
: away as a fake -or at least a Frankenwatch-
: is the dial.

: Last year I have spent A LOT of time to
: recreate the 'checkered flag' Heuer logo and
: the thing I noticed first is that all
: vintage Heuer's (and most other vintage
: watches for that matter) have -what I call-
: a 'closed-flat-top-4'.

: This one has got a cheap font 'open-4'. Is this
: a (new) tell tale for fakes? I've never seen
: anyone else mention it...

: I'm far from an expert...it's just something I
: noticed when recreating the logo (as good as
: finished). I want to know what you guys
: think of my little theory.

: Thanks for listening,
: Filip