What's the motivation for determining originality here? I have a bit of a philosophy on originality. Perhaps the perspective will help, perhaps not.

1. If originality preserves value or history - stay original.
2. If originality preserves something you wish to preserve - stay original.
3. If you have no desire to invest time, $, energy in taking something from originality you don't care for to something you really like - stay original.
4. If you have something original that you would like a lot better if it were updated, and you have the desire and ability to update - update it.

As I look at the bike pictures, my own personal assessment is that neither #1 nor #2 applies. Then, I would have to choose between #3 and #4 .

If jgedwa is around and wishes to assist us in a philosophical discussion, he's the resident master.