Ron I think it happens already, provenance will be even more important in the future, e.g. bought from Jeff Stein or a reputable Heuer dealer.
I would guess around 70 % of the vintage Heuer watches offered on ebay were somehow altered during their lifecycles by changing pushers, glasses, straps, move parts....
Rare Nos is another story as supply is even more limited. It is easier to get good information today than 10 years ago, which is good news for any new collector.
Quite a recent trend is the hunt for spareparts, some rare parts are even more expensive than complete watches. Now we could raise the discussion in which direction does this change the market ?
Best Arno

: I have been wondering about it a for a while and would like the
: input of the others. As, this may be happening sooner or later
: with one of our beloved models.
: What I am talking about? I am talking about the steady rising of
: prices for some models to such an extent that they become of
: interest to the professional makers of Replicas.

: Now with Replica I am not talking about a Monaco with redone dial,
: or some Cartavia Franken.
: I guess we have all already seen what i mean here. Take for example
: the vintage Rolex Daytona which is available in a near to
: perfect copies. Hard to distinguish from the real one for
: laymen. Until you open it up and see the cheap calibre or study
: the crystal looking for the tiny Rolex crown which has been
: lasered into it.

: Well, with 1133b's at levels between 7000 and 8000 Euros, PVD's
: between 15.000 and 20.000, there will surely be some
: "inventive" minds sooner or later who will decide to
: make replicas of these types. Maybe also Sifferts.And this would
: mean fake cases, fake dials, hands etc. This would open up a
: new, not so bright, era

: I do not think there will be many obstacles for those people who do
: this.For sure, if prices go up further. These watches mostly
: come from low income countries where labour is cheap and the
: level of craftmanship is still high.

: How see others see this?Or is this un unlikely scenario?

: Ron