It took me a while in your email to understand that originality meant all original components. I usually interpret originality as creativity... creating an original... However, looking at your usage, it makes sense enough that I went to a dictionary sie to make sure I wasn't crazy.

But, anyway... For a collectible bike, it is best to have all original components if it is a museum piece, and some people like them that way for riding as well. There is some prestige associated with owning an all original classic...

However, the attitude of most people in this forum tends to freely allow for expression through creative upgrades while retaining the classic features of a bike. But, there are some that have fine machines that are all original, and they get the forum equivalent of oohs and aahhs every time they are shown or discussed.

Ask many people here, and it seems the answer would be that if a bike isn't to be ridden, then there is an issue. If it is ridden more, then many will see the changes as beneficial.

There is a difference between the car folks and the bicycle folks in general (but not universally) that for cars, one that looks unused and is never driven is the best... in the bicycling world, the beauty of pristene bikes is appreciated, but you will almost always get comments like "Ride it!"

However, if there are organized bike shows like there are car shows, I am sure that they place a high value on bikes being in original condition.

EDIT: And to answer another of your questions, the monetary value of most bikes, regardless of the original components will not usually be enough to make your decision... although the usual comment is to hold on to the original components "just in case."