Oh, that Beetle ROCKS!

I guess my take on this topic goes back to something I read a while ago - there's a difference between a restoration and a renovation. I think of a restoration as being an attempt to make the item (bike, car, whatever) being restored approximate as closely as possible the way it looked when it came off the showroom floor. All original parts, original colors, original accessories, etc. If you're doing a restoration, you don't have a lot of wiggle room on this stuff.

On the other hand, a renovation involves no such devotion to authenticity. Renovating a bike (or car, or whatever) allows you the freedom to do whatever suits your fancy - install alloy wheels if you like! Put a Schwinn saddle on a Rudge if you like the way it looks and feels! Have the frame painted paisley, if it suits your mood! The only limits are your budget, your personal sense of taste, and the use to which you intend to put the object of your renovation.

Of course, this definitional distinction is entirely arbitrary, but that's generally true of most definitions.