To confuse the argument, I have a 56cm Cannondale 2.8 frame. It started life, and my ownership, as a stock R500 of 1995 vintage. The only original factory installed components are the right/rear brifter, the left crank arm, and the right crank arm and spider.

Both derailers are Shimano 105 (5600)
The front shifter is a Suntour downtube.
The front brake lever is a Shimano RSX
The brakes are Shimano Ultegra (6600)
The chainrings are now Sugino 30/40/50
The headset is now Campagnolo Record (1" threaded)
The fork is now Nashbar carbon fiber (only 1" threaded steerer I could find)
The seatpost is a Kalloy Guizzo
The BB has been replaced twice since purchase
The chain is a SRAM PC-58
I've used five different cassettes trying to find my best gearing, but the orginal cassette has been worn out and now adorns a shop wall I don't work at anymore.
Wheels? I still have the factory orginal RSX hubs laced to Mavic CXP 23 rims, but I also have a set of Shimano 600 hubs laced to Mavic Open Pro rims and a newly aquired Roval areo wheelset that uses a freewheel.

So is that custom?