I had 2 what I would call all original bikes (with exception of tires/saddle).
The first was my Trek 670, 1985 model which I bought with all OEM equiptment
still on it. The tires were dry rotted and the saddle was in the worst shape I have
ever seen, leather cover gone and the foam dry and crumbly. While cleaning and tuning it
up I replaced the bar/stem combo with a set of Modolo that matched the brakes that were OEM.
The campy NR gruppo had all matching dates (1984) and they stayed on the bike.
When I sold it (to another BF member ) I replaced the bar/stem with the original which I kept.
I replaced the saddle with the same model that came standard with the bike (Concor).
The other original bike is my 74 RIH, it has campy N.R. derailleurs. brakes hubs etc. but a SR super
mighty crankset (very typical of dutch bikes). The saddle also was a mess (unica nitor buffalo)
so I replaced that with a san marco regal. that and tires are the only changes I will make to
this bike, ever.
all the others I put whatever I feel like on them at the time I'm building it up, and sometimes
even that changes.
The only caveat I have for my bikes is that they are safe (i.e. no imminent failures).

collector? nah, more of an enthusiast.

marty