I change whatever it takes to make a bike ridable.

Of course, I don't ride anything so collectible that I feel bad doing it.

I currently have an early 70's Sears 10 speed with cotterless crank, LX RD and 6 speed Megarange freewheel... along with upgraded wheels (aluminum rims), technomic stem and Nitto bars with Tektro brake levers and stem mounted indexed 6 speed Shimano shifters.

The headset, frame, fork seatpost and brakes are original, everything else is a replacement, and decidedly not period correct.

My Schwinn Voyageur has exactly the same original components, with everything else replaced with current Shimano 105 level components.